Repository: streamlit/streamlit

Issue:
Watchdog error on install (Mac)
I've tried to install it in a MAC using PIP and PIP3 and I get the same error:

Command "/usr/local/opt/python/bin/python3.7 -u -c "import setuptools, tokenize;__file__='/private/var/folders/0s/rkvsfhzn2930_3902mpks9lm0000gn/T/pip-install-3cscl6kq/watchdog/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /private/var/folders/0s/rkvsfhzn2930_3902mpks9lm0000gn/T/pip-record-qr49cvd0/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /private/var/folders/0s/rkvsfhzn2930_3902mpks9lm0000gn/T/pip-install-3cscl6kq/watchdog/

I'm using: 
macOS Mojave 10.14.5



Discussion:
Hi @naurojr , thanks for the bug report

I haven't seen that issue before... can you try the solution proposed in this StackOverflow answer: https://stackoverflow.com/questions/31498495/error-when-installing-using-pip
I'm having the same issue. The solution from StackOverflow did not solve it, as far as I can tell setuptools is properly installed.

I'm using macOS Mojave 10.14.5
pip version 18.1
Python 3.6.7 

The error is being raised when installing `watchdog`.

``` pip install streamlit
Collecting streamlit
  Using cached https://files.pythonhosted.org/packages/d0/99/f8166f0baac96f2ea4d634749331bf78d8830db9991fc8086e828dca8959/streamlit-0.47.4-py2.py3-none-any.whl
Requirement already satisfied: base58 in ./anaconda3/lib/python3.6/site-packages (from streamlit) (1.0.3)
Requirement already satisfied: click>=7.0 in ./anaconda3/lib/python3.6/site-packages (from streamlit) (7.0)
Requirement already satisfied: blinker in ./anaconda3/lib/python3.6/site-packages (from streamlit) (1.4)
Requirement already satisfied: protobuf>=3.6.0 in ./anaconda3/lib/python3.6/site-packages (from streamlit) (3.6.1)
Requirement already satisfied: pillow!=5.1.0 in ./anaconda3/lib/python3.6/site-packages (from streamlit) (5.3.0)
Requirement already satisfied: botocore in ./anaconda3/lib/python3.6/site-packages (from streamlit) (1.12.227)
Requirement already satisfied: tzlocal in ./anaconda3/lib/python3.6/site-packages (from streamlit) (1.5.1)
Requirement already satisfied: pandas in ./anaconda3/lib/python3.6/site-packages (from streamlit) (0.23.4)
Requirement already satisfied: altair>=3.2.0 in ./anaconda3/lib/python3.6/site-packages (from streamlit) (3.2.0)
Requirement already satisfied: tornado<6.0,>=5.0 in ./anaconda3/lib/python3.6/site-packages (from streamlit) (5.1.1)
Collecting watchdog (from streamlit)
  Using cached https://files.pythonhosted.org/packages/bb/e3/5a55d48a29300160779f0a0d2776d17c1b762a2039b36de528b093b87d5b/watchdog-0.9.0.tar.gz
Requirement already satisfied: requests in ./anaconda3/lib/python3.6/site-packages (from streamlit) (2.22.0)
Collecting validators (from streamlit)
Requirement already satisfied: enum-compat in ./anaconda3/lib/python3.6/site-packages (from streamlit) (0.0.2)
Requirement already satisfied: astor in ./anaconda3/lib/python3.6/site-packages (from streamlit) (0.7.1)
Requirement already satisfied: numpy in ./anaconda3/lib/python3.6/site-packages (from streamlit) (1.16.4)
Requirement already satisfied: toml in ./anaconda3/lib/python3.6/site-packages (from streamlit) (0.10.0)
Requirement already satisfied: future in ./anaconda3/lib/python3.6/site-packages (from streamlit) (0.17.1)
Requirement already satisfied: boto3 in ./anaconda3/lib/python3.6/site-packages (from streamlit) (1.3.1)
Requirement already satisfied: six>=1.9 in ./anaconda3/lib/python3.6/site-packages (from protobuf>=3.6.0->streamlit) (1.12.0)
Requirement already satisfied: setuptools in ./anaconda3/lib/python3.6/site-packages (from protobuf>=3.6.0->streamlit) (41.2.0)
Requirement already satisfied: urllib3<1.26,>=1.20; python_version >= "3.4" in ./anaconda3/lib/python3.6/site-packages (from botocore->streamlit) (1.22)
Requirement already satisfied: docutils<0.16,>=0.10 in ./anaconda3/lib/python3.6/site-packages (from botocore->streamlit) (0.14)
Requirement already satisfied: python-dateutil<3.0.0,>=2.1; python_version >= "2.7" in ./anaconda3/lib/python3.6/site-packages (from botocore->streamlit) (2.7.5)
Requirement already satisfied: jmespath<1.0.0,>=0.7.1 in ./anaconda3/lib/python3.6/site-packages (from botocore->streamlit) (0.9.3)
Requirement already satisfied: pytz in ./anaconda3/lib/python3.6/site-packages (from tzlocal->streamlit) (2018.7)
Requirement already satisfied: toolz in ./anaconda3/lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (0.9.0)
Requirement already satisfied: jsonschema in ./anaconda3/lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (3.0.0a3)
Requirement already satisfied: entrypoints in ./anaconda3/lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (0.2.3)
Requirement already satisfied: jinja2 in ./anaconda3/lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (2.10)
Requirement already satisfied: PyYAML>=3.10 in ./anaconda3/lib/python3.6/site-packages (from watchdog->streamlit) (3.13)
Requirement already satisfied: argh>=0.24.1 in ./anaconda3/lib/python3.6/site-packages (from watchdog->streamlit) (0.26.2)
Requirement already satisfied: pathtools>=0.1.1 in ./anaconda3/lib/python3.6/site-packages (from watchdog->streamlit) (0.1.2)
Requirement already satisfied: chardet<3.1.0,>=3.0.2 in ./anaconda3/lib/python3.6/site-packages (from requests->streamlit) (3.0.4)
Requirement already satisfied: idna<2.9,>=2.5 in ./anaconda3/lib/python3.6/site-packages (from requests->streamlit) (2.6)
Requirement already satisfied: certifi>=2017.4.17 in ./anaconda3/lib/python3.6/site-packages (from requests->streamlit) (2019.6.16)
Requirement already satisfied: decorator>=3.4.0 in ./anaconda3/lib/python3.6/site-packages (from validators->streamlit) (4.3.0)
Requirement already satisfied: attrs>=17.4.0 in ./anaconda3/lib/python3.6/site-packages (from jsonschema->altair>=3.2.0->streamlit) (18.2.0)
Requirement already satisfied: pyrsistent>=0.14.0 in ./anaconda3/lib/python3.6/site-packages (from jsonschema->altair>=3.2.0->streamlit) (0.14.5)
Requirement already satisfied: MarkupSafe>=0.23 in ./anaconda3/lib/python3.6/site-packages (from jinja2->altair>=3.2.0->streamlit) (1.0)
Building wheels for collected packages: watchdog
  Running setup.py bdist_wheel for watchdog ... error
  Complete output from command /Users/mkleinbort/anaconda3/bin/python -u -c "import setuptools, tokenize;__file__='/private/var/folders/ps/xprs7v4n48n67fmb3sxn70nc0000gn/T/pip-install-bzqcb80r/watchdog/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" bdist_wheel -d /private/var/folders/ps/xprs7v4n48n67fmb3sxn70nc0000gn/T/pip-wheel-a6fmbdhf --python-tag cp36:
  running bdist_wheel
  running build
  running build_py
  creating build
  creating build/lib.macosx-10.7-x86_64-3.6
  creating build/lib.macosx-10.7-x86_64-3.6/watchdog
  copying src/watchdog/watchmedo.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
  copying src/watchdog/version.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
  copying src/watchdog/events.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
  copying src/watchdog/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
  creating build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  copying src/watchdog/utils/unicode_paths.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  copying src/watchdog/utils/compat.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  copying src/watchdog/utils/win32stat.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  copying src/watchdog/utils/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  copying src/watchdog/utils/dirsnapshot.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  copying src/watchdog/utils/delayed_queue.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  copying src/watchdog/utils/platform.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  copying src/watchdog/utils/importlib2.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  copying src/watchdog/utils/bricks.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  copying src/watchdog/utils/echo.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  copying src/watchdog/utils/event_backport.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  copying src/watchdog/utils/decorators.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
  creating build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
  copying src/watchdog/observers/fsevents.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
  copying src/watchdog/observers/inotify.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
  copying src/watchdog/observers/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
  copying src/watchdog/observers/api.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
  copying src/watchdog/observers/inotify_buffer.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
  copying src/watchdog/observers/winapi.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
  copying src/watchdog/observers/read_directory_changes.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
  copying src/watchdog/observers/kqueue.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
  copying src/watchdog/observers/inotify_c.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
  copying src/watchdog/observers/polling.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
  copying src/watchdog/observers/fsevents2.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
  creating build/lib.macosx-10.7-x86_64-3.6/watchdog/tricks
  copying src/watchdog/tricks/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/tricks
  running egg_info
  writing src/watchdog.egg-info/PKG-INFO
  writing dependency_links to src/watchdog.egg-info/dependency_links.txt
  writing entry points to src/watchdog.egg-info/entry_points.txt
  writing requirements to src/watchdog.egg-info/requires.txt
  writing top-level names to src/watchdog.egg-info/top_level.txt
  reading manifest file 'src/watchdog.egg-info/SOURCES.txt'
  reading manifest template 'MANIFEST.in'
  warning: no files found matching '*.h' under directory 'src'
  writing manifest file 'src/watchdog.egg-info/SOURCES.txt'
  running build_ext
  building '_watchdog_fsevents' extension
  creating build/temp.macosx-10.7-x86_64-3.6
  creating build/temp.macosx-10.7-x86_64-3.6/src
  gcc -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I/Users/mkleinbort/anaconda3/include -arch x86_64 -I/Users/mkleinbort/anaconda3/include -arch x86_64 -DWATCHDOG_VERSION_STRING="0.9.0" -DWATCHDOG_VERSION_MAJOR=0 -DWATCHDOG_VERSION_MINOR=9 -DWATCHDOG_VERSION_BUILD=0 -I/Users/mkleinbort/anaconda3/include/python3.6m -c src/watchdog_fsevents.c -o build/temp.macosx-10.7-x86_64-3.6/src/watchdog_fsevents.o -std=c99 -pedantic -Wall -Wextra -fPIC -Wno-error=unused-command-line-argument-hard-error-in-future
  warning: unknown warning option '-Werror=unused-command-line-argument-hard-error-in-future'; did you mean '-Werror=unused-command-line-argument'? [-Wunknown-warning-option]
  In file included from src/watchdog_fsevents.c:24:
  In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:24:
  In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/AE.framework/Headers/AE.h:20:
  In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/CarbonCore.framework/Headers/CarbonCore.h:208:
  In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/CarbonCore.framework/Headers/HFSVolumes.h:25:
  /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/hfs/hfs_format.h:794:2: error: unknown type name 'uuid_string_t'; did you mean 'io_string_t'?
          uuid_string_t   ext_jnl_uuid;
          ^
  /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/device/device_types.h:89:33: note: 'io_string_t' declared here
  typedef char                    io_string_t[512];
                                  ^
  In file included from src/watchdog_fsevents.c:24:
  In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:24:
  In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/AE.framework/Headers/AE.h:20:
  In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/CarbonCore.framework/Headers/CarbonCore.h:208:
  In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/CarbonCore.framework/Headers/HFSVolumes.h:25:
  /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/hfs/hfs_format.h:796:20: error: use of undeclared identifier 'uuid_string_t'
          char            reserved[JIB_RESERVED_SIZE];
                                   ^
  /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/hfs/hfs_format.h:787:61: note: expanded from macro 'JIB_RESERVED_SIZE'
  #define JIB_RESERVED_SIZE  ((32*sizeof(u_int32_t)) - sizeof(uuid_string_t) - 48)
                                                              ^
  src/watchdog_fsevents.c:136:63: warning: unused parameter 'stream_ref' [-Wunused-parameter]
  watchdog_FSEventStreamCallback(ConstFSEventStreamRef          stream_ref,
                                                                ^
  src/watchdog_fsevents.c:141:63: warning: unused parameter 'event_ids' [-Wunused-parameter]
                                 const FSEventStreamEventId     event_ids[])
                                                                ^
  src/watchdog_fsevents.c:334:30: warning: unused parameter 'self' [-Wunused-parameter]
  watchdog_add_watch(PyObject *self, PyObject *args)
                               ^
  src/watchdog_fsevents.c:417:32: warning: unused parameter 'self' [-Wunused-parameter]
  watchdog_read_events(PyObject *self, PyObject *args)
                                 ^
  src/watchdog_fsevents.c:466:33: warning: unused parameter 'self' [-Wunused-parameter]
  watchdog_remove_watch(PyObject *self, PyObject *watch)
                                  ^
  src/watchdog_fsevents.c:491:25: warning: unused parameter 'self' [-Wunused-parameter]
  watchdog_stop(PyObject *self, PyObject *emitter_thread)
                          ^
  src/watchdog_fsevents.c:531:10: warning: missing field 'ml_meth' initializer [-Wmissing-field-initializers]
      {NULL},
           ^
  src/watchdog_fsevents.c:602:1: warning: missing field 'm_slots' initializer [-Wmissing-field-initializers]
  };
  ^
  9 warnings and 2 errors generated.
  error: command 'gcc' failed with exit status 1
  
  ----------------------------------------
  Failed building wheel for watchdog
  Running setup.py clean for watchdog
Failed to build watchdog
Installing collected packages: watchdog, validators, streamlit
  Running setup.py install for watchdog ... error
    Complete output from command /Users/mkleinbort/anaconda3/bin/python -u -c "import setuptools, tokenize;__file__='/private/var/folders/ps/xprs7v4n48n67fmb3sxn70nc0000gn/T/pip-install-bzqcb80r/watchdog/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /private/var/folders/ps/xprs7v4n48n67fmb3sxn70nc0000gn/T/pip-record-by59l6f6/install-record.txt --single-version-externally-managed --compile:
    running install
    running build
    running build_py
    creating build
    creating build/lib.macosx-10.7-x86_64-3.6
    creating build/lib.macosx-10.7-x86_64-3.6/watchdog
    copying src/watchdog/watchmedo.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
    copying src/watchdog/version.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
    copying src/watchdog/events.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
    copying src/watchdog/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
    creating build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/unicode_paths.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/compat.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/win32stat.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/dirsnapshot.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/delayed_queue.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/platform.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/importlib2.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/bricks.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/echo.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/event_backport.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/decorators.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
    creating build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/fsevents.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/inotify.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/api.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/inotify_buffer.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/winapi.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/read_directory_changes.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/kqueue.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/inotify_c.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/polling.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/fsevents2.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
    creating build/lib.macosx-10.7-x86_64-3.6/watchdog/tricks
    copying src/watchdog/tricks/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/tricks
    running egg_info
    writing src/watchdog.egg-info/PKG-INFO
    writing dependency_links to src/watchdog.egg-info/dependency_links.txt
    writing entry points to src/watchdog.egg-info/entry_points.txt
    writing requirements to src/watchdog.egg-info/requires.txt
    writing top-level names to src/watchdog.egg-info/top_level.txt
    reading manifest file 'src/watchdog.egg-info/SOURCES.txt'
    reading manifest template 'MANIFEST.in'
    warning: no files found matching '*.h' under directory 'src'
    writing manifest file 'src/watchdog.egg-info/SOURCES.txt'
    running build_ext
    building '_watchdog_fsevents' extension
    creating build/temp.macosx-10.7-x86_64-3.6
    creating build/temp.macosx-10.7-x86_64-3.6/src
    gcc -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I/Users/mkleinbort/anaconda3/include -arch x86_64 -I/Users/mkleinbort/anaconda3/include -arch x86_64 -DWATCHDOG_VERSION_STRING="0.9.0" -DWATCHDOG_VERSION_MAJOR=0 -DWATCHDOG_VERSION_MINOR=9 -DWATCHDOG_VERSION_BUILD=0 -I/Users/mkleinbort/anaconda3/include/python3.6m -c src/watchdog_fsevents.c -o build/temp.macosx-10.7-x86_64-3.6/src/watchdog_fsevents.o -std=c99 -pedantic -Wall -Wextra -fPIC -Wno-error=unused-command-line-argument-hard-error-in-future
    warning: unknown warning option '-Werror=unused-command-line-argument-hard-error-in-future'; did you mean '-Werror=unused-command-line-argument'? [-Wunknown-warning-option]
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/AE.framework/Headers/AE.h:20:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/CarbonCore.framework/Headers/CarbonCore.h:208:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/CarbonCore.framework/Headers/HFSVolumes.h:25:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/hfs/hfs_format.h:794:2: error: unknown type name 'uuid_string_t'; did you mean 'io_string_t'?
            uuid_string_t   ext_jnl_uuid;
            ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/device/device_types.h:89:33: note: 'io_string_t' declared here
    typedef char                    io_string_t[512];
                                    ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/AE.framework/Headers/AE.h:20:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/CarbonCore.framework/Headers/CarbonCore.h:208:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/CarbonCore.framework/Headers/HFSVolumes.h:25:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/hfs/hfs_format.h:796:20: error: use of undeclared identifier 'uuid_string_t'
            char            reserved[JIB_RESERVED_SIZE];
                                     ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/hfs/hfs_format.h:787:61: note: expanded from macro 'JIB_RESERVED_SIZE'
    #define JIB_RESERVED_SIZE  ((32*sizeof(u_int32_t)) - sizeof(uuid_string_t) - 48)
                                                                ^
    src/watchdog_fsevents.c:136:63: warning: unused parameter 'stream_ref' [-Wunused-parameter]
    watchdog_FSEventStreamCallback(ConstFSEventStreamRef          stream_ref,
                                                                  ^
    src/watchdog_fsevents.c:141:63: warning: unused parameter 'event_ids' [-Wunused-parameter]
                                   const FSEventStreamEventId     event_ids[])
                                                                  ^
    src/watchdog_fsevents.c:334:30: warning: unused parameter 'self' [-Wunused-parameter]
    watchdog_add_watch(PyObject *self, PyObject *args)
                                 ^
    src/watchdog_fsevents.c:417:32: warning: unused parameter 'self' [-Wunused-parameter]
    watchdog_read_events(PyObject *self, PyObject *args)
                                   ^
    src/watchdog_fsevents.c:466:33: warning: unused parameter 'self' [-Wunused-parameter]
    watchdog_remove_watch(PyObject *self, PyObject *watch)
                                    ^
    src/watchdog_fsevents.c:491:25: warning: unused parameter 'self' [-Wunused-parameter]
    watchdog_stop(PyObject *self, PyObject *emitter_thread)
                            ^
    src/watchdog_fsevents.c:531:10: warning: missing field 'ml_meth' initializer [-Wmissing-field-initializers]
        {NULL},
             ^
    src/watchdog_fsevents.c:602:1: warning: missing field 'm_slots' initializer [-Wmissing-field-initializers]
    };
    ^
    9 warnings and 2 errors generated.
    error: command 'gcc' failed with exit status 1
    
    ----------------------------------------
Command "/Users/mkleinbort/anaconda3/bin/python -u -c "import setuptools, tokenize;__file__='/private/var/folders/ps/xprs7v4n48n67fmb3sxn70nc0000gn/T/pip-install-bzqcb80r/watchdog/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /private/var/folders/ps/xprs7v4n48n67fmb3sxn70nc0000gn/T/pip-record-by59l6f6/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /private/var/folders/ps/xprs7v4n48n67fmb3sxn70nc0000gn/T/pip-install-bzqcb80r/watchdog/```
Same error when installing watchdog for me. 
I could not install streamlit in Windows Comandprompt but I could install it in AnacondaPrompt so you should try it !!
I saw a comment from [Mark Conway](https://medium.com/@MarkConway/you-may-get-an-error-installing-watchdog-on-the-mac-with-the-pip-install-command-first-do-this-bb277dafe5f1) saying that you need to install watchdog first and then install streamlit

```
conda install -c conda-forge watchdog

Then:

pip install streamlit
```
That works for me with 
Python 3.7 
macOS Mojave 10.14.5
conda 4.7.10
# Summary

This issue came up for another user today in live testing. The user was using a several-year's old MacBook 

* conda: `4.5`
* pip: `19.3.1`
* which pip: `/usr/local/anaconda3/bin/pip`

## Imporant note: the user's `gcc` installation was broken

```
XYZ-MacBook-Pro:~ xzy$ gcc
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
XYZ-MacBook-Pro:~ xzy$ which gcc
/usr/bin/gcc
XYZ-MacBook-Pro:~ xzy$ gcc
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
```

## Side note: trying to install xcode didn't help

```
XYZ-MacBook-Pro:~ xzy$ xcode-select --install
xcode-select: note: install requested for command line developer tools
XYZ-MacBook-Pro:~ xzy$ xcode-select --reset
xcode-select: error: --reset must be run as root (e.g. `sudo xcode-select --reset`).
XYZ-MacBook-Pro:~ xzy$ sudo xcode-select --reset
Password:
XYZ-MacBook-Pro:~ xzy$ gcc
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
```

## Workaround

The workaround described above *did work*:

```
conda install -c conda-forge watchdog
pip install streamlit
```

# Observed Behavior

Streamlit failed to install watchdog and the whole installation faled.

```
XYZ-MacBook-Pro:~ xzy$ pip install streamlit
Collecting streamlit
Downloading https://files.pythonhosted.org/packages/9f/31/24d170bb25102b76eec6884dc1356fb6bdc8c9c82e347ce47baed76f2a7b/streamlit-0.49.0-py2.py3-none-any.whl (5.1MB)
|████████████████████████████████| 5.1MB 1.3MB/s
Collecting tornado<6.0,>=5.0
Downloading https://files.pythonhosted.org/packages/e6/78/6e7b5af12c12bdf38ca9bfe863fcaf53dc10430a312d0324e76c1e5ca426/tornado-5.1.1.tar.gz (516kB)
|████████████████████████████████| 522kB 27.5MB/s
Requirement already satisfied: numpy in /usr/local/anaconda3/lib/python3.6/site-packages (from streamlit) (1.13.3)
Collecting enum-compat
Downloading https://files.pythonhosted.org/packages/55/ae/467bc4509246283bb59746e21a1a2f5a8aecbef56b1fa6eaca78cd438c8b/enum_compat-0.0.3-py3-none-any.whl
Collecting watchdog
Downloading https://files.pythonhosted.org/packages/bb/e3/5a55d48a29300160779f0a0d2776d17c1b762a2039b36de528b093b87d5b/watchdog-0.9.0.tar.gz (85kB)
|████████████████████████████████| 92kB 19.2MB/s
Collecting tzlocal
Downloading https://files.pythonhosted.org/packages/ef/99/53bd1ac9349262f59c1c421d8fcc2559ae8a5eeffed9202684756b648d33/tzlocal-2.0.0-py2.py3-none-any.whl
Requirement already satisfied: pillow!=5.1.0 in /usr/local/anaconda3/lib/python3.6/site-packages (from streamlit) (4.2.1)
Collecting altair>=3.2.0
Downloading https://files.pythonhosted.org/packages/34/24/3e50e226a79db1bb1427bf8c58cc4dc7c2f74c39b728af005f4b11d1760c/altair-3.2.0-py2.py3-none-any.whl (596kB)
|████████████████████████████████| 604kB 21.1MB/s
Collecting blinker
Downloading https://files.pythonhosted.org/packages/1b/51/e2a9f3b757eb802f61dc1f2b09c8c99f6eb01cf06416c0671253536517b6/blinker-1.4.tar.gz (111kB)
|████████████████████████████████| 112kB 29.1MB/s
Collecting botocore
Downloading https://files.pythonhosted.org/packages/f4/72/5d81c5eb90ce94e438875d166ed98724bbe24be1283ec650cdfe2107cd3e/botocore-1.13.0-py2.py3-none-any.whl (5.3MB)
|████████████████████████████████| 5.3MB 129kB/s
Collecting protobuf>=3.6.0
Downloading https://files.pythonhosted.org/packages/76/c2/08685ae86ee1f5a45839e779726640ba981e629da2999ebce17e62639c9a/protobuf-3.10.0-cp36-cp36m-macosx_10_9_intel.whl (1.4MB)
|████████████████████████████████| 1.4MB 622kB/s
Collecting boto3
Downloading https://files.pythonhosted.org/packages/f1/63/56d49c9ac4b00e56fa9a954e995cc08098b1adebb4fa5654e19ff734567d/boto3-1.10.0-py2.py3-none-any.whl (128kB)
|████████████████████████████████| 133kB 35.9MB/s
Requirement already satisfied: requests in /usr/local/anaconda3/lib/python3.6/site-packages (from streamlit) (2.18.4)
Collecting astor
Downloading https://files.pythonhosted.org/packages/d1/4f/950dfae467b384fc96bc6469de25d832534f6b4441033c39f914efd13418/astor-0.8.0-py2.py3-none-any.whl
Collecting future
Downloading https://files.pythonhosted.org/packages/3f/bf/57733d44afd0cf67580658507bd11d3ec629612d5e0e432beb4b8f6fbb04/future-0.18.1.tar.gz (828kB)
|████████████████████████████████| 829kB 33.7MB/s
Collecting toml
Downloading https://files.pythonhosted.org/packages/a2/12/ced7105d2de62fa7c8fb5fce92cc4ce66b57c95fb875e9318dba7f8c5db0/toml-0.10.0-py2.py3-none-any.whl
Collecting validators
Downloading https://files.pythonhosted.org/packages/b2/b7/5fc43b7dba2a35362b2f5ce39dbee835c48898e2458910c3af810240fbaa/validators-0.14.0.tar.gz
Requirement already satisfied: pandas in /usr/local/anaconda3/lib/python3.6/site-packages (from streamlit) (0.20.3)
Collecting base58
Downloading https://files.pythonhosted.org/packages/09/b2/21ac9591f055acc145afead895edeb73bbd69d95cf366fc5c2233f2434cb/base58-1.0.3-py3-none-any.whl
Collecting click>=7.0
Downloading https://files.pythonhosted.org/packages/fa/37/45185cb5abbc30d7257104c434fe0b07e5a195a6847506c074527aa599ec/Click-7.0-py2.py3-none-any.whl (81kB)
|████████████████████████████████| 81kB 587kB/s
Requirement already satisfied: PyYAML>=3.10 in /usr/local/anaconda3/lib/python3.6/site-packages (from watchdog->streamlit) (3.12)
Collecting argh>=0.24.1
Downloading https://files.pythonhosted.org/packages/06/1c/e667a7126f0b84aaa1c56844337bf0ac12445d1beb9c8a6199a7314944bf/argh-0.26.2-py2.py3-none-any.whl
Collecting pathtools>=0.1.1
Downloading https://files.pythonhosted.org/packages/e7/7f/470d6fcdf23f9f3518f6b0b76be9df16dcc8630ad409947f8be2eb0ed13a/pathtools-0.1.2.tar.gz
Requirement already satisfied: pytz in /usr/local/anaconda3/lib/python3.6/site-packages (from tzlocal->streamlit) (2017.2)
Requirement already satisfied: olefile in /usr/local/anaconda3/lib/python3.6/site-packages (from pillow!=5.1.0->streamlit) (0.44)
Requirement already satisfied: entrypoints in /usr/local/anaconda3/lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (0.2.3)
Requirement already satisfied: toolz in /usr/local/anaconda3/lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (0.8.2)
Requirement already satisfied: jinja2 in /usr/local/anaconda3/lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (2.9.6)
Requirement already satisfied: six in /usr/local/anaconda3/lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (1.11.0)
Requirement already satisfied: jsonschema in /usr/local/anaconda3/lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (2.6.0)
Requirement already satisfied: docutils<0.16,>=0.10 in /usr/local/anaconda3/lib/python3.6/site-packages (from botocore->streamlit) (0.14)
Requirement already satisfied: python-dateutil<3.0.0,>=2.1; python_version >= "2.7" in /usr/local/anaconda3/lib/python3.6/site-packages (from botocore->streamlit) (2.6.1)
Collecting jmespath<1.0.0,>=0.7.1
Downloading https://files.pythonhosted.org/packages/83/94/7179c3832a6d45b266ddb2aac329e101367fbdb11f425f13771d27f225bb/jmespath-0.9.4-py2.py3-none-any.whl
Requirement already satisfied: urllib3<1.26,>=1.20; python_version >= "3.4" in /usr/local/anaconda3/lib/python3.6/site-packages (from botocore->streamlit) (1.22)
Requirement already satisfied: setuptools in /usr/local/anaconda3/lib/python3.6/site-packages (from protobuf>=3.6.0->streamlit) (36.5.0.post20170921)
Collecting s3transfer<0.3.0,>=0.2.0
Downloading https://files.pythonhosted.org/packages/16/8a/1fc3dba0c4923c2a76e1ff0d52b305c44606da63f718d14d3231e21c51b0/s3transfer-0.2.1-py2.py3-none-any.whl (70kB)
|████████████████████████████████| 71kB 16.9MB/s
Requirement already satisfied: chardet<3.1.0,>=3.0.2 in /usr/local/anaconda3/lib/python3.6/site-packages (from requests->streamlit) (3.0.4)
Requirement already satisfied: idna<2.7,>=2.5 in /usr/local/anaconda3/lib/python3.6/site-packages (from requests->streamlit) (2.6)
Requirement already satisfied: certifi>=2017.4.17 in /usr/local/anaconda3/lib/python3.6/site-packages (from requests->streamlit) (2018.8.13)
Requirement already satisfied: decorator>=3.4.0 in /usr/local/anaconda3/lib/python3.6/site-packages (from validators->streamlit) (4.1.2)
Requirement already satisfied: MarkupSafe>=0.23 in /usr/local/anaconda3/lib/python3.6/site-packages (from jinja2->altair>=3.2.0->streamlit) (1.0)
Building wheels for collected packages: tornado, watchdog, blinker, future, validators, pathtools
Building wheel for tornado (setup.py) ... done
Created wheel for tornado: filename=tornado-5.1.1-cp36-cp36m-macosx_10_7_x86_64.whl size=451577 sha256=69e9baf28e0dfdabc85a6e0723274fe66e184d6a76ca71b66ff17f499e65adf0
Stored in directory: /Users/xzy/Library/Caches/pip/wheels/6d/e1/ce/f4ee2fa420cc6b940123c64992b81047816d0a9fad6b879325
Building wheel for watchdog (setup.py) ... error
ERROR: Command errored out with exit status 1:
command: /usr/local/anaconda3/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/kw/mwxq2mrj5gg80807xw4q4dlh0000gn/T/pip-install-789how3d/watchdog/setup.py'"'"'; __file__='"'"'/private/var/folders/kw/mwxq2mrj5gg80807xw4q4dlh0000gn/T/pip-install-789how3d/watchdog/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' bdist_wheel -d /private/var/folders/kw/mwxq2mrj5gg80807xw4q4dlh0000gn/T/pip-wheel-mdkwefwn --python-tag cp36
cwd: /private/var/folders/kw/mwxq2mrj5gg80807xw4q4dlh0000gn/T/pip-install-789how3d/watchdog/
Complete output (54 lines):
running bdist_wheel
running build
running build_py
creating build
creating build/lib.macosx-10.7-x86_64-3.6
creating build/lib.macosx-10.7-x86_64-3.6/watchdog
copying src/watchdog/watchmedo.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
copying src/watchdog/version.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
copying src/watchdog/events.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
copying src/watchdog/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
creating build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/unicode_paths.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/compat.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/win32stat.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/dirsnapshot.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/delayed_queue.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/platform.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/importlib2.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/bricks.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/echo.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/event_backport.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/decorators.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
creating build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/fsevents.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/inotify.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/api.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/inotify_buffer.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/winapi.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/read_directory_changes.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/kqueue.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/inotify_c.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/polling.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/fsevents2.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
creating build/lib.macosx-10.7-x86_64-3.6/watchdog/tricks
copying src/watchdog/tricks/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/tricks
running egg_info
writing src/watchdog.egg-info/PKG-INFO
writing dependency_links to src/watchdog.egg-info/dependency_links.txt
writing entry points to src/watchdog.egg-info/entry_points.txt
writing requirements to src/watchdog.egg-info/requires.txt
writing top-level names to src/watchdog.egg-info/top_level.txt
reading manifest file 'src/watchdog.egg-info/SOURCES.txt'
reading manifest template 'MANIFEST.in'
warning: no files found matching '*.h' under directory 'src'
writing manifest file 'src/watchdog.egg-info/SOURCES.txt'
running build_ext
building '_watchdog_fsevents' extension
creating build/temp.macosx-10.7-x86_64-3.6
creating build/temp.macosx-10.7-x86_64-3.6/src
gcc -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I/usr/local/anaconda3/include -arch x86_64 -I/usr/local/anaconda3/include -arch x86_64 -DWATCHDOG_VERSION_STRING="0.9.0" -DWATCHDOG_VERSION_MAJOR=0 -DWATCHDOG_VERSION_MINOR=9 -DWATCHDOG_VERSION_BUILD=0 -I/usr/local/anaconda3/include/python3.6m -c src/watchdog_fsevents.c -o build/temp.macosx-10.7-x86_64-3.6/src/watchdog_fsevents.o -std=c99 -pedantic -Wall -Wextra -fPIC -Wno-error=unused-command-line-argument-hard-error-in-future
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
error: command 'gcc' failed with exit status 1
----------------------------------------
ERROR: Failed building wheel for watchdog
Running setup.py clean for watchdog
Building wheel for blinker (setup.py) ... done
Created wheel for blinker: filename=blinker-1.4-cp36-none-any.whl size=14272 sha256=c2384b03cec62998cc9d65afb113137d97a1970d8e2d582e86644d73fb424ff7
Stored in directory: /Users/xzy/Library/Caches/pip/wheels/92/a0/00/8690a57883956a301d91cf4ec999cc0b258b01e3f548f86e89
Building wheel for future (setup.py) ... done
Created wheel for future: filename=future-0.18.1-cp36-none-any.whl size=492672 sha256=a8ae36c129004ff5c8488ef36687d490de2a5c7208fe6cbc55fae8920beffa52
Stored in directory: /Users/xzy/Library/Caches/pip/wheels/74/bc/50/ae030267a192919b289f84661cfeb5573cf383841c543e8696
Building wheel for validators (setup.py) ... done
Created wheel for validators: filename=validators-0.14.0-cp36-none-any.whl size=17355 sha256=741e0d9507434c326514fa49f74f2251ff3eb9e1a4c6a1c11a37599945d835a4
Stored in directory: /Users/xzy/Library/Caches/pip/wheels/52/ad/d4/c5ddfd117381a9c46fdc4a1d15eb688a81e6e821f5c69d9056
Building wheel for pathtools (setup.py) ... done
Created wheel for pathtools: filename=pathtools-0.1.2-cp36-none-any.whl size=8640 sha256=3c7d3bbc27a3c8c3b42cc24d853c3208d27fd16f6002b06047c651712081777f
Stored in directory: /Users/xzy/Library/Caches/pip/wheels/0b/04/79/c3b0c3a0266a3cb4376da31e5bfe8bba0c489246968a68e843
Successfully built tornado blinker future validators pathtools
Failed to build watchdog
Installing collected packages: tornado, enum-compat, argh, pathtools, watchdog, tzlocal, altair, blinker, jmespath, botocore, protobuf, s3transfer, boto3, astor, future, toml, validators, base58, click, streamlit
Found existing installation: tornado 4.5.2
Uninstalling tornado-4.5.2:
Successfully uninstalled tornado-4.5.2
Running setup.py install for watchdog ... error
ERROR: Command errored out with exit status 1:
command: /usr/local/anaconda3/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/kw/mwxq2mrj5gg80807xw4q4dlh0000gn/T/pip-install-789how3d/watchdog/setup.py'"'"'; __file__='"'"'/private/var/folders/kw/mwxq2mrj5gg80807xw4q4dlh0000gn/T/pip-install-789how3d/watchdog/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /private/var/folders/kw/mwxq2mrj5gg80807xw4q4dlh0000gn/T/pip-record-1r2j0l4a/install-record.txt --single-version-externally-managed --compile
cwd: /private/var/folders/kw/mwxq2mrj5gg80807xw4q4dlh0000gn/T/pip-install-789how3d/watchdog/
Complete output (54 lines):
running install
running build
running build_py
creating build
creating build/lib.macosx-10.7-x86_64-3.6
creating build/lib.macosx-10.7-x86_64-3.6/watchdog
copying src/watchdog/watchmedo.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
copying src/watchdog/version.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
copying src/watchdog/events.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
copying src/watchdog/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog
creating build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/unicode_paths.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/compat.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/win32stat.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/dirsnapshot.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/delayed_queue.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/platform.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/importlib2.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/bricks.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/echo.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/event_backport.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
copying src/watchdog/utils/decorators.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/utils
creating build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/fsevents.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/inotify.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/api.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/inotify_buffer.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/winapi.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/read_directory_changes.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/kqueue.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/inotify_c.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/polling.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
copying src/watchdog/observers/fsevents2.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/observers
creating build/lib.macosx-10.7-x86_64-3.6/watchdog/tricks
copying src/watchdog/tricks/__init__.py -> build/lib.macosx-10.7-x86_64-3.6/watchdog/tricks
running egg_info
writing src/watchdog.egg-info/PKG-INFO
writing dependency_links to src/watchdog.egg-info/dependency_links.txt
writing entry points to src/watchdog.egg-info/entry_points.txt
writing requirements to src/watchdog.egg-info/requires.txt
writing top-level names to src/watchdog.egg-info/top_level.txt
reading manifest file 'src/watchdog.egg-info/SOURCES.txt'
reading manifest template 'MANIFEST.in'
warning: no files found matching '*.h' under directory 'src'
writing manifest file 'src/watchdog.egg-info/SOURCES.txt'
running build_ext
building '_watchdog_fsevents' extension
creating build/temp.macosx-10.7-x86_64-3.6
creating build/temp.macosx-10.7-x86_64-3.6/src
gcc -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I/usr/local/anaconda3/include -arch x86_64 -I/usr/local/anaconda3/include -arch x86_64 -DWATCHDOG_VERSION_STRING="0.9.0" -DWATCHDOG_VERSION_MAJOR=0 -DWATCHDOG_VERSION_MINOR=9 -DWATCHDOG_VERSION_BUILD=0 -I/usr/local/anaconda3/include/python3.6m -c src/watchdog_fsevents.c -o build/temp.macosx-10.7-x86_64-3.6/src/watchdog_fsevents.o -std=c99 -pedantic -Wall -Wextra -fPIC -Wno-error=unused-command-line-argument-hard-error-in-future
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
error: command 'gcc' failed with exit status 1
----------------------------------------
ERROR: Command errored out with exit status 1: /usr/local/anaconda3/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/kw/mwxq2mrj5gg80807xw4q4dlh0000gn/T/pip-install-789how3d/watchdog/setup.py'"'"'; __file__='"'"'/private/var/folders/kw/mwxq2mrj5gg80807xw4q4dlh0000gn/T/pip-install-789how3d/watchdog/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /private/var/folders/kw/mwxq2mrj5gg80807xw4q4dlh0000gn/T/pip-record-1r2j0l4a/install-record.txt --single-version-externally-managed --compile Check the logs for full command output.
```
I've been reading the bugs above and have a suggestion for how this could be fixed.

# Desired Behavior

1. At install, automagically **detect that `watchdog` won't be installable** and **use the python fallback**.
2. After a (presumably) successful installation and upon a first `streamlit` command run, suggest that the user install watchdog on thier own (ideally recommending `conda` since they're in a conda environment.) As decribed [here](https://discuss.streamlit.io/t/error-installing-streamlit-on-os-x/399/5), the correct command is:

```
conda install -c conda-forge watchdog
```

## More Details

This desired behavior presumes we can detect environments where watchdog won't work. Two possibilities:

1. On the extreme of guaranteeing a successful installation, we could say that streamlit work for _any_ conda environment.
2. On the other extreme of trying to maximize the chance that watchdog is installed automatically, we could try to pre-figure out whether pip installing watchdog will fail. This would be easy in the case just above because `gcc` wasn't working, but I'm not sure that would cover every case users are seeing.

**I think we should do (1)** because:

1. This approach maximizes the probability that installation will succeed.
2. It's not clear (to me) from the examples above how we could design such a test that the watchdog install will work. (I *do not* think a valid watchdog installation check would be to try installing `watchog` manually in `setup.py` since this would break dependency checking.)
Can someone try the following? Depending on your setup, a different combination of the commands below *should* work

### This will bring up a prompt to install the necessary command line tools.
sudo xcode-select --install

### Agree to the license afterwards
sudo xcodebuild -license

### You may need to run reset
sudo xcode-select --reset

### Agree to the license afterwards
sudo xcodebuild -license

### If you'd only like the tools without xcode, download and install them from apple
https://developer.apple.com/download/more/

### Agree to the license afterwards
sudo xcodebuild -license

### Try setting the path for the active developer directory to one of these locations. Try each one if no success.
sudo xcode-select --switch /Library/Developer/CommandLineTools
sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer
sudo xcode-select --switch /

Note,  `/Applications/Xcode.app/Contents/Developer` maybe should be `/Applications/Xcode.app`

### Agree to the license afterwards
sudo xcodebuild -license

Note, not sure exactly when the license needs to be agreed to so I've included it after multiple steps.

### After each set of commands, try the following to verify success
`which xcrun`
`gcc`

### And finally :D
`pip install streamlit` 

@jrhone : This might fix the problem for specific users, but I think we need a [solution that works even if they haven't properly setup xcode tools](https://github.com/streamlit/streamlit/issues/283#issuecomment-546115467), right?
Sounds good.

@naurojr , @mkleinbort , @gchiaramonte , could you try the following commands and share the output with me for each one?

`which xcrun`
`xcrun`
`which gcc`
`gcc`
`gcc --version`
@jrhone : Should we close this issue?
Hey @treuille, still haven't got confirmation from a user that our solution works as we expect. I think @tvst wanted to get it in the release with the hope that it was OK. Would be nice to get the output from the commands in the above comment or a thumbs up from a user that the fix is good before closing.
@jrhome this is what I see when running the commands

(streamlit) Nauros-MacBook-Pro:~ therebelideamobile$ which xcrun
/usr/bin/xcrun
(streamlit) Nauros-MacBook-Pro:~ therebelideamobile$ xcrun
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
(streamlit) Nauros-MacBook-Pro:~ therebelideamobile$ which gcc
/usr/bin/gcc
(streamlit) Nauros-MacBook-Pro:~ therebelideamobile$ gcc
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
(streamlit) Nauros-MacBook-Pro:~ therebelideamobile$ gcc --version
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
(streamlit) Nauros-MacBook-Pro:~ therebelideamobile$ 


Note however that I was able to install Streamlit using the workaround from @TannerGilbert  

conda install -c conda-forge watchdog
pip install streamlit


Thanks @naurojr !! Looks like our fix should work OK then. You should be able to install the latest version of streamlit (0.50.2) without the workaround without error.

@treuille moving this issue to `Done`, it'll get closed whenever Thiago clears out the `Done` column.

> conda install -c conda-forge watchdog
> pip install streamlit

This workaround works for me globally, but not in `venv`. Any idea? Thanks!
I am also unable to load Streamlit onto my Mac and I am using Python 3.8.2/macOS Catalina Version 10.15.3.  I also tried installing Streamlit within PyCharm and from the terminal prompt and continue to receive an error message that appears to be related to Watchdog as mentioned above.   
This issue is still present I'm afraid. 

**Versions:**
* OSX 10.15.4 (Catalina)
* Python 3.7.1
* pip 20.0.2
* streamlit 0.58.0
* 
    ```console
    $ gcc --version
    Configured with: --prefix=/Library/Developer/CommandLineTools/usr --with-gxx-include-dir=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/4.2.1
    Apple clang version 11.0.3 (clang-1103.0.32.59)
    Target: x86_64-apple-darwin19.4.0
    Thread model: posix
    InstalledDir: /Library/Developer/CommandLineTools/usr/bin
    ```

I've already tried removing and reinstalling xcode tools but to no avail. 
<details>
  <summary>Output from trying to pip install in a clean virtualenv (brace yourself):</summary>

```console
$ pip install streamlit==0.58.0
[ bunch of output from other dependencies installing successfully, and then... ]
Failed to build watchdog
Installing collected packages: pyparsing, packaging, idna, chardet, certifi, requests, ipython-genutils, traitlets, pickleshare, parso, jedi, ptyprocess, pexpect, backcall, wcwidth, prompt-toolkit, appnope, pygments, ipython, pyzmq, tornado, jupyter-core, jupyter-client, ipykernel, nbformat, terminado, prometheus-client, Send2Trash, defusedxml, webencodings, bleach, testpath, pandocfilters, mistune, nbconvert, notebook, widgetsnbextension, ipywidgets, pydeck, protobuf, enum-compat, toml, watchdog, s3transfer, boto3, pillow, streamlit
    Running setup.py install for watchdog ... error
ERROR: Command errored out with exit status 1:
     command: /Users/cw0504/.virtualenvs/tmp-6a9e5203a17eb84/bin/python3.7 -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/4p/5572k17s0_91n0xvt7hcgxq80000gp/T/pip-install-nddtyj_f/watchdog/setup.py'"'"'; __file__='"'"'/private/var/folders/4p/5572k17s0_91n0xvt7hcgxq80000gp/T/pip-install-nddtyj_f/watchdog/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /private/var/folders/4p/5572k17s0_91n0xvt7hcgxq80000gp/T/pip-record-raf_sp5z/install-record.txt --single-version-externally-managed --compile --install-headers /Users/cw0504/.virtualenvs/tmp-6a9e5203a17eb84/include/site/python3.7/watchdog
         cwd: /private/var/folders/4p/5572k17s0_91n0xvt7hcgxq80000gp/T/pip-install-nddtyj_f/watchdog/
    Complete output (298 lines):
    running install
    running build
    running build_py
    creating build
    creating build/lib.macosx-10.14-x86_64-3.7
    creating build/lib.macosx-10.14-x86_64-3.7/watchdog
    copying src/watchdog/watchmedo.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog
    copying src/watchdog/version.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog
    copying src/watchdog/events.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog
    copying src/watchdog/__init__.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog
    creating build/lib.macosx-10.14-x86_64-3.7/watchdog/utils
    copying src/watchdog/utils/unicode_paths.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/utils
    copying src/watchdog/utils/compat.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/utils
    copying src/watchdog/utils/win32stat.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/utils
    copying src/watchdog/utils/__init__.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/utils
    copying src/watchdog/utils/dirsnapshot.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/utils
    copying src/watchdog/utils/delayed_queue.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/utils
    copying src/watchdog/utils/platform.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/utils
    copying src/watchdog/utils/bricks.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/utils
    copying src/watchdog/utils/echo.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/utils
    creating build/lib.macosx-10.14-x86_64-3.7/watchdog/observers
    copying src/watchdog/observers/fsevents.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/observers
    copying src/watchdog/observers/inotify.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/observers
    copying src/watchdog/observers/__init__.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/observers
    copying src/watchdog/observers/api.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/observers
    copying src/watchdog/observers/inotify_buffer.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/observers
    copying src/watchdog/observers/winapi.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/observers
    copying src/watchdog/observers/read_directory_changes.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/observers
    copying src/watchdog/observers/kqueue.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/observers
    copying src/watchdog/observers/inotify_c.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/observers
    copying src/watchdog/observers/polling.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/observers
    copying src/watchdog/observers/fsevents2.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/observers
    creating build/lib.macosx-10.14-x86_64-3.7/watchdog/tricks
    copying src/watchdog/tricks/__init__.py -> build/lib.macosx-10.14-x86_64-3.7/watchdog/tricks
    running egg_info
    writing src/watchdog.egg-info/PKG-INFO
    writing dependency_links to src/watchdog.egg-info/dependency_links.txt
    writing entry points to src/watchdog.egg-info/entry_points.txt
    writing requirements to src/watchdog.egg-info/requires.txt
    writing top-level names to src/watchdog.egg-info/top_level.txt
    reading manifest file 'src/watchdog.egg-info/SOURCES.txt'
    reading manifest template 'MANIFEST.in'
    warning: no files found matching '*.h' under directory 'src'
    writing manifest file 'src/watchdog.egg-info/SOURCES.txt'
    running build_ext
    building '_watchdog_fsevents' extension
    creating build/temp.macosx-10.14-x86_64-3.7
    creating build/temp.macosx-10.14-x86_64-3.7/src
    clang -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include -DWATCHDOG_VERSION_STRING="0.10.2" -DWATCHDOG_VERSION_MAJOR=0 -DWATCHDOG_VERSION_MINOR=10 -DWATCHDOG_VERSION_BUILD=2 -I/Users/cw0504/.pyenv/versions/3.7.1/include/python3.7m -c src/watchdog_fsevents.c -o build/temp.macosx-10.14-x86_64-3.7/src/watchdog_fsevents.o -std=c99 -pedantic -Wall -Wextra -fPIC -Wno-nullability-completeness -Wno-nullability-extension -Wno-newline-eof -Wno-error=unused-command-line-argument
    In file included from src/watchdog_fsevents.c:22:
    In file included from /Users/cw0504/.pyenv/versions/3.7.1/include/python3.7m/Python.h:100:
    In file included from /Users/cw0504/.pyenv/versions/3.7.1/include/python3.7m/traceback.h:8:
    In file included from /Users/cw0504/.pyenv/versions/3.7.1/include/python3.7m/pystate.h:11:
    In file included from /Users/cw0504/.pyenv/versions/3.7.1/include/python3.7m/pythread.h:114:
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/pthread.h:331:6: warning: macro expansion producing 'defined' has undefined behavior [-Wexpansion-to-defined]
    #if !_PTHREAD_SWIFT_IMPORTER_NULLABILITY_COMPAT
         ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/pthread.h:200:2: note: expanded from macro '_PTHREAD_SWIFT_IMPORTER_NULLABILITY_COMPAT'
            defined(SWIFT_CLASS_EXTRA) && (!defined(SWIFT_SDK_OVERLAY_PTHREAD_EPOCH) || (SWIFT_SDK_OVERLAY_PTHREAD_EPOCH < 1))
            ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/pthread.h:331:6: warning: macro expansion producing 'defined' has undefined behavior [-Wexpansion-to-defined]
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/pthread.h:200:34: note: expanded from macro '_PTHREAD_SWIFT_IMPORTER_NULLABILITY_COMPAT'
            defined(SWIFT_CLASS_EXTRA) && (!defined(SWIFT_SDK_OVERLAY_PTHREAD_EPOCH) || (SWIFT_SDK_OVERLAY_PTHREAD_EPOCH < 1))
                                            ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/pthread.h:540:6: warning: macro expansion producing 'defined' has undefined behavior [-Wexpansion-to-defined]
    #if !_PTHREAD_SWIFT_IMPORTER_NULLABILITY_COMPAT
         ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/pthread.h:200:2: note: expanded from macro '_PTHREAD_SWIFT_IMPORTER_NULLABILITY_COMPAT'
            defined(SWIFT_CLASS_EXTRA) && (!defined(SWIFT_SDK_OVERLAY_PTHREAD_EPOCH) || (SWIFT_SDK_OVERLAY_PTHREAD_EPOCH < 1))
            ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/pthread.h:540:6: warning: macro expansion producing 'defined' has undefined behavior [-Wexpansion-to-defined]
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/pthread.h:200:34: note: expanded from macro '_PTHREAD_SWIFT_IMPORTER_NULLABILITY_COMPAT'
            defined(SWIFT_CLASS_EXTRA) && (!defined(SWIFT_SDK_OVERLAY_PTHREAD_EPOCH) || (SWIFT_SDK_OVERLAY_PTHREAD_EPOCH < 1))
                                            ^
    In file included from src/watchdog_fsevents.c:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreFoundation.framework/Headers/CoreFoundation.h:60:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreFoundation.framework/Headers/CFPropertyList.h:17:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreFoundation.framework/Headers/CFStream.h:16:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreFoundation.framework/Headers/CFURL.h:1159:83: error: expected ','
        kCFURLBookmarkCreationWithSecurityScope API_AVAILABLE(macos(10.7), macCatalyst(13.0))  API_UNAVAILABLE(ios, watchos, tvos) = ( 1UL << 11 ), // Mac OS X 10.7.3 and later, include information in the bookmark data which allows the same sandboxed process to access the resource after being relaunched
                                                                                      ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreFoundation.framework/Headers/CFURL.h:1160:98: error: expected ','
        kCFURLBookmarkCreationSecurityScopeAllowOnlyReadAccess API_AVAILABLE(macos(10.7), macCatalyst(13.0)) API_UNAVAILABLE(ios, watchos, tvos) = ( 1UL << 12 ), // Mac OS X 10.7.3 and later, if used with kCFURLBookmarkCreationWithSecurityScope, at resolution time only read access to the resource will be granted
                                                                                                     ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreFoundation.framework/Headers/CFURL.h:1170:85: error: expected ','
        kCFURLBookmarkResolutionWithSecurityScope API_AVAILABLE(macos(10.7), macCatalyst(13.0)) API_UNAVAILABLE(ios, watchos, tvos) = ( 1UL << 10 ), // Mac OS X 10.7.3 and later, use the secure information included at creation time to provide the ability to access the resource in a sandboxed process.
                                                                                        ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:142:74: error: expected ','
    typedef struct CF_BRIDGED_TYPE(id) __SecKeychainItem *SecKeychainItemRef API_UNAVAILABLE(ios, watchos, tvos, macCatalyst);
                                                                             ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:148:78: error: expected ','
    typedef struct CF_BRIDGED_TYPE(id) __SecKeychainSearch *SecKeychainSearchRef API_UNAVAILABLE(ios, watchos, tvos, macCatalyst);
                                                                                 ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:154:36: error: expected ','
    typedef OSType SecKeychainAttrType API_UNAVAILABLE(ios, watchos, tvos, macCatalyst);
                                       ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:163:8: error: expected ','
    struct API_UNAVAILABLE(ios, watchos, tvos, macCatalyst) SecKeychainAttribute
           ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:169:58: error: expected ','
    typedef struct SecKeychainAttribute SecKeychainAttribute API_UNAVAILABLE(ios, watchos, tvos, macCatalyst);
                                                             ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:175:55: error: expected ','
    typedef SecKeychainAttribute *SecKeychainAttributePtr API_UNAVAILABLE(ios, watchos, tvos, macCatalyst);
                                                          ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:183:8: error: expected ','
    struct API_UNAVAILABLE(ios, watchos, tvos, macCatalyst) SecKeychainAttributeList
           ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:188:66: error: expected ','
    typedef struct SecKeychainAttributeList SecKeychainAttributeList API_UNAVAILABLE(ios, watchos, tvos, macCatalyst);
                                                                     ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:194:34: error: expected ','
    typedef UInt32 SecKeychainStatus API_UNAVAILABLE(ios, watchos, tvos, macCatalyst);
                                     ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:200:86: error: expected ','
    typedef struct CF_BRIDGED_TYPE(id) __SecTrustedApplication *SecTrustedApplicationRef API_UNAVAILABLE(ios, watchos, tvos, macCatalyst);
                                                                                         ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:206:62: error: expected ','
    typedef struct CF_BRIDGED_TYPE(id) __SecAccess *SecAccessRef API_UNAVAILABLE(ios, watchos, tvos, macCatalyst);
                                                                 ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:216:56: error: expected ','
    typedef struct CF_BRIDGED_TYPE(id) __SecACL *SecACLRef API_UNAVAILABLE(ios, watchos, tvos, macCatalyst);
                                                           ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:222:66: error: expected ','
    typedef struct CF_BRIDGED_TYPE(id) __SecPassword *SecPasswordRef API_UNAVAILABLE(ios, watchos, tvos, macCatalyst);
                                                                     ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:232:8: error: expected ','
    struct API_UNAVAILABLE(ios, watchos, tvos, macCatalyst) SecKeychainAttributeInfo
           ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:26:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentityBase.h:23:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecBase.h:238:66: error: expected ','
    typedef struct SecKeychainAttributeInfo SecKeychainAttributeInfo API_UNAVAILABLE(ios, watchos, tvos, macCatalyst);
                                                                     ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    In file included from src/watchdog_fsevents.c:24:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:39:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:43:
    In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/Security.h:28:
    /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Security.framework/Headers/SecCertificate.h:182:82: error: expected ','
        API_DEPRECATED_WITH_REPLACEMENT("SecCertificateCopyKey", macos(10.3, 10.14)) API_UNAVAILABLE(ios, tvos, watchos, macCatalyst);
                                                                                     ^
    /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/os/availability.h:93:114: note: expanded from macro 'API_UNAVAILABLE'
        #define API_UNAVAILABLE(...) __API_UNAVAILABLE_GET_MACRO(__VA_ARGS__,__API_UNAVAILABLE6, __API_UNAVAILABLE5, __API_UNAVAILABLE4,__API_UNAVAILABLE3,__API_UNAVAILABLE2,__API_UNAVAILABLE1, 0)(__VA_ARGS__)
                                                                                                                     ^
    fatal error: too many errors emitted, stopping now [-ferror-limit=]
    4 warnings and 20 errors generated.
    error: command 'clang' failed with exit status 1
    ----------------------------------------
ERROR: Command errored out with exit status 1: /Users/cw0504/.virtualenvs/tmp-6a9e5203a17eb84/bin/python3.7 -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/4p/5572k17s0_91n0xvt7hcgxq80000gp/T/pip-install-nddtyj_f/watchdog/setup.py'"'"'; __file__='"'"'/private/var/folders/4p/5572k17s0_91n0xvt7hcgxq80000gp/T/pip-install-nddtyj_f/watchdog/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /private/var/folders/4p/5572k17s0_91n0xvt7hcgxq80000gp/T/pip-record-raf_sp5z/install-record.txt --single-version-externally-managed --compile --install-headers /Users/cw0504/.virtualenvs/tmp-6a9e5203a17eb84/include/site/python3.7/watchdog Check the logs for full command output.
```
</details>

This solution worked for me: https://github.com/gorakhargosh/watchdog/issues/628#issuecomment-581480649
I spent ~10 minutes looking into this to see if there's an easy patch for Watchdog, but I don't think there is. Recording some notes for posterity:

- Xcode used to let you choose which macOS SDKs you wanted to install
- No longer! Now, in Catalina, it installs 10.15 and 10.14 SDKs
- If [removing the 10.14 SDK](https://github.com/gorakhargosh/watchdog/issues/628#issuecomment-581480649) fixes the issue for people we should figure out:
-- Why is the 10.14 SDK being used? (Watchdog doesn't specify it, and the default SDK is 10.15)
-- Is this a bug in the macOS SDK, or is Watchdog doing something bad?
-- (Watchdog is not looking for a specific macOS SDK, so I don't think we can say “just don’t build against the Mojave SDK!”)
Per the forum just now, deleting the 10.14 SDK wasn't sufficient

https://discuss.streamlit.io/t/unable-to-install-on-osx-10-15-5/3571/3?u=randyzwitch
has this been resolved?  i am still running into the watchdog dependency error even when I try the suggested solve. 

conda install -c conda-forge watchdog
pip install streamlit

really want to try streamlit
Hey All - I'm still running into this issue. I really want to try streamlit but can't seem to get watchdog to install properly. 

Here's what I am running. I've tried to install streamlit, and I've tried to first install watchdog but I run into the same error either way. I am currently trying to install it in my active virtual environment. 

OSX 10.14.6 (Mojave)
Python 3.6.9
pip 18.1 


Here's the full output I get:
Collecting streamlit
  Downloading https://files.pythonhosted.org/packages/73/a9/f3b4d005cd00ce435da3573bedacc1aff7eff76b312a215ed02c6297f56d/streamlit-0.64.0-py2.py3-none-any.whl (7.1MB)
    100% |████████████████████████████████| 7.1MB 5.4MB/s 
Requirement already satisfied: validators in ./lib/python3.6/site-packages (from streamlit) (0.17.1)
Requirement already satisfied: altair>=3.2.0 in ./lib/python3.6/site-packages (from streamlit) (4.1.0)
Requirement already satisfied: requests in ./lib/python3.6/site-packages (from streamlit) (2.24.0)
Requirement already satisfied: botocore>=1.13.44 in ./lib/python3.6/site-packages (from streamlit) (1.17.36)
Requirement already satisfied: tornado>=5.0 in ./lib/python3.6/site-packages (from streamlit) (6.0.4)
Collecting toml (from streamlit)
  Downloading https://files.pythonhosted.org/packages/9f/e1/1b40b80f2e1663a6b9f497123c11d7d988c0919abbf3c3f2688e448c5363/toml-0.10.1-py2.py3-none-any.whl
Requirement already satisfied: boto3 in ./lib/python3.6/site-packages (from streamlit) (1.14.36)
Requirement already satisfied: click>=7.0 in ./lib/python3.6/site-packages (from streamlit) (7.1.2)
Requirement already satisfied: packaging in ./lib/python3.6/site-packages (from streamlit) (20.4)
Collecting tzlocal (from streamlit)
  Downloading https://files.pythonhosted.org/packages/5d/94/d47b0fd5988e6b7059de05720a646a2930920fff247a826f61674d436ba4/tzlocal-2.1-py2.py3-none-any.whl
Requirement already satisfied: cachetools>=4.0 in ./lib/python3.6/site-packages (from streamlit) (4.1.1)
Requirement already satisfied: protobuf>=3.6.0 in ./lib/python3.6/site-packages (from streamlit) (3.12.4)
Collecting watchdog (from streamlit)
  Downloading https://files.pythonhosted.org/packages/0e/06/121302598a4fc01aca942d937f4a2c33430b7181137b35758913a8db10ad/watchdog-0.10.3.tar.gz (94kB)
    100% |████████████████████████████████| 102kB 21.4MB/s 
Collecting base58 (from streamlit)
  Downloading https://files.pythonhosted.org/packages/3c/03/58572025c77b9e6027155b272a1b96298e711cd4f95c24967f7137ab0c4b/base58-2.0.1-py3-none-any.whl
Collecting pydeck>=0.1.dev5 (from streamlit)
  Downloading https://files.pythonhosted.org/packages/94/0f/05708169885fa9adca54a47ce75b020bc6c16ccc3533dd4e483ea6f5e3eb/pydeck-0.4.1-py2.py3-none-any.whl (4.4MB)
    100% |████████████████████████████████| 4.4MB 5.7MB/s 
Requirement already satisfied: blinker in ./lib/python3.6/site-packages (from streamlit) (1.4)
Requirement already satisfied: pandas>=0.21.0 in ./lib/python3.6/site-packages (from streamlit) (1.1.0)
Collecting enum-compat (from streamlit)
  Downloading https://files.pythonhosted.org/packages/55/ae/467bc4509246283bb59746e21a1a2f5a8aecbef56b1fa6eaca78cd438c8b/enum_compat-0.0.3-py3-none-any.whl
Requirement already satisfied: numpy in ./lib/python3.6/site-packages (from streamlit) (1.19.1)
Collecting pillow>=6.2.0 (from streamlit)
  Downloading https://files.pythonhosted.org/packages/04/8f/c42f534b73680f501858a8c7171705a55c7347c86419b74fa585370c8306/Pillow-7.2.0-cp36-cp36m-macosx_10_10_x86_64.whl (2.2MB)
    100% |████████████████████████████████| 2.2MB 11.4MB/s 
Requirement already satisfied: astor in ./lib/python3.6/site-packages (from streamlit) (0.8.1)
Requirement already satisfied: python-dateutil in ./lib/python3.6/site-packages (from streamlit) (2.8.1)
Requirement already satisfied: pyarrow in ./lib/python3.6/site-packages (from streamlit) (1.0.0)
Requirement already satisfied: six>=1.4.0 in ./lib/python3.6/site-packages (from validators->streamlit) (1.15.0)
Requirement already satisfied: decorator>=3.4.0 in ./lib/python3.6/site-packages (from validators->streamlit) (4.4.2)
Requirement already satisfied: jsonschema in ./lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (3.2.0)
Requirement already satisfied: entrypoints in ./lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (0.3)
Requirement already satisfied: toolz in ./lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (0.10.0)
Requirement already satisfied: jinja2 in ./lib/python3.6/site-packages (from altair>=3.2.0->streamlit) (2.11.2)
Requirement already satisfied: chardet<4,>=3.0.2 in ./lib/python3.6/site-packages (from requests->streamlit) (3.0.4)
Requirement already satisfied: certifi>=2017.4.17 in ./lib/python3.6/site-packages (from requests->streamlit) (2020.6.20)
Requirement already satisfied: urllib3!=1.25.0,!=1.25.1,<1.26,>=1.21.1 in ./lib/python3.6/site-packages (from requests->streamlit) (1.25.10)
Requirement already satisfied: idna<3,>=2.5 in ./lib/python3.6/site-packages (from requests->streamlit) (2.10)
Requirement already satisfied: jmespath<1.0.0,>=0.7.1 in ./lib/python3.6/site-packages (from botocore>=1.13.44->streamlit) (0.10.0)
Requirement already satisfied: docutils<0.16,>=0.10 in ./lib/python3.6/site-packages (from botocore>=1.13.44->streamlit) (0.15.2)
Requirement already satisfied: s3transfer<0.4.0,>=0.3.0 in ./lib/python3.6/site-packages (from boto3->streamlit) (0.3.3)
Requirement already satisfied: pyparsing>=2.0.2 in ./lib/python3.6/site-packages (from packaging->streamlit) (2.4.7)
Requirement already satisfied: pytz in ./lib/python3.6/site-packages (from tzlocal->streamlit) (2020.1)
Requirement already satisfied: setuptools in ./lib/python3.6/site-packages (from protobuf>=3.6.0->streamlit) (40.6.2)
Requirement already satisfied: pathtools>=0.1.1 in ./lib/python3.6/site-packages (from watchdog->streamlit) (0.1.2)
Collecting ipywidgets>=7.0.0 (from pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/56/a0/dbcf5881bb2f51e8db678211907f16ea0a182b232c591a6d6f276985ca95/ipywidgets-7.5.1-py2.py3-none-any.whl (121kB)
    100% |████████████████████████████████| 122kB 19.2MB/s 
Collecting ipykernel>=5.1.2; python_version >= "3.4" (from pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/52/19/c2812690d8b340987eecd2cbc18549b1d130b94c5d97fcbe49f5f8710edf/ipykernel-5.3.4-py3-none-any.whl (120kB)
    100% |████████████████████████████████| 122kB 23.2MB/s 
Collecting traitlets>=4.3.2 (from pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/ca/ab/872a23e29cec3cf2594af7e857f18b687ad21039c1f9b922fac5b9b142d5/traitlets-4.3.3-py2.py3-none-any.whl (75kB)
    100% |████████████████████████████████| 81kB 16.9MB/s 
Requirement already satisfied: importlib-metadata; python_version < "3.8" in ./lib/python3.6/site-packages (from jsonschema->altair>=3.2.0->streamlit) (1.7.0)
Requirement already satisfied: pyrsistent>=0.14.0 in ./lib/python3.6/site-packages (from jsonschema->altair>=3.2.0->streamlit) (0.16.0)
Requirement already satisfied: attrs>=17.4.0 in ./lib/python3.6/site-packages (from jsonschema->altair>=3.2.0->streamlit) (19.3.0)
Requirement already satisfied: MarkupSafe>=0.23 in ./lib/python3.6/site-packages (from jinja2->altair>=3.2.0->streamlit) (1.1.1)
Collecting nbformat>=4.2.0 (from ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/4d/d1/b568bd35f95321f152f594b3647cd080e96d3347843ff2fa34dce871b8bf/nbformat-5.0.7-py3-none-any.whl (170kB)
    100% |████████████████████████████████| 174kB 18.0MB/s 
Collecting ipython>=4.0.0; python_version >= "3.3" (from ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/23/6a/210816c943c9aeeb29e4e18a298f14bf0e118fe222a23e13bfcc2d41b0a4/ipython-7.16.1-py3-none-any.whl (785kB)
    100% |████████████████████████████████| 788kB 21.3MB/s 
Collecting widgetsnbextension~=3.5.0 (from ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/6c/7b/7ac231c20d2d33c445eaacf8a433f4e22c60677eb9776c7c5262d7ddee2d/widgetsnbextension-3.5.1-py2.py3-none-any.whl (2.2MB)
    100% |████████████████████████████████| 2.2MB 11.2MB/s 
Collecting jupyter-client (from ipykernel>=5.1.2; python_version >= "3.4"->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/48/2e/6d48ae4ef0c9aa1383b3186349472a01bb38dacb2162a4a4370525d3f2a4/jupyter_client-6.1.6-py3-none-any.whl (108kB)
    100% |████████████████████████████████| 112kB 16.7MB/s 
Collecting appnope; platform_system == "Darwin" (from ipykernel>=5.1.2; python_version >= "3.4"->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/87/a9/7985e6a53402f294c8f0e8eff3151a83f1fb901fa92909bb3ff29b4d22af/appnope-0.1.0-py2.py3-none-any.whl
Collecting ipython-genutils (from traitlets>=4.3.2->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/fa/bc/9bd3b5c2b4774d5f33b2d544f1460be9df7df2fe42f352135381c347c69a/ipython_genutils-0.2.0-py2.py3-none-any.whl
Requirement already satisfied: zipp>=0.5 in ./lib/python3.6/site-packages (from importlib-metadata; python_version < "3.8"->jsonschema->altair>=3.2.0->streamlit) (3.1.0)
Collecting jupyter-core (from nbformat>=4.2.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/63/0d/df2d17cdf389cea83e2efa9a4d32f7d527ba78667e0153a8e676e957b2f7/jupyter_core-4.6.3-py2.py3-none-any.whl (83kB)
    100% |████████████████████████████████| 92kB 16.1MB/s 
Collecting backcall (from ipython>=4.0.0; python_version >= "3.3"->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/4c/1c/ff6546b6c12603d8dd1070aa3c3d273ad4c07f5771689a7b69a550e8c951/backcall-0.2.0-py2.py3-none-any.whl
Collecting pickleshare (from ipython>=4.0.0; python_version >= "3.3"->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/9a/41/220f49aaea88bc6fa6cba8d05ecf24676326156c23b991e80b3f2fc24c77/pickleshare-0.7.5-py2.py3-none-any.whl
Collecting jedi>=0.10 (from ipython>=4.0.0; python_version >= "3.3"->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/c3/d4/36136b18daae06ad798966735f6c3fb96869c1be9f8245d2a8f556e40c36/jedi-0.17.2-py2.py3-none-any.whl (1.4MB)
    100% |████████████████████████████████| 1.4MB 16.4MB/s 
Collecting pexpect; sys_platform != "win32" (from ipython>=4.0.0; python_version >= "3.3"->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/39/7b/88dbb785881c28a102619d46423cb853b46dbccc70d3ac362d99773a78ce/pexpect-4.8.0-py2.py3-none-any.whl (59kB)
    100% |████████████████████████████████| 61kB 9.7MB/s 
Collecting prompt-toolkit!=3.0.0,!=3.0.1,<3.1.0,>=2.0.0 (from ipython>=4.0.0; python_version >= "3.3"->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/e4/a7/81b39aa50e9284fe2cb21cc7fb7de7817b224172d42793fd57451d38842b/prompt_toolkit-3.0.5-py3-none-any.whl (351kB)
    100% |████████████████████████████████| 358kB 13.5MB/s 
Collecting pygments (from ipython>=4.0.0; python_version >= "3.3"->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/2d/68/106af3ae51daf807e9cdcba6a90e518954eb8b70341cee52995540a53ead/Pygments-2.6.1-py3-none-any.whl (914kB)
    100% |████████████████████████████████| 921kB 21.2MB/s 
Collecting notebook>=4.4.1 (from widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/98/c0/b96c891d8a999aae2b7fcf8f440038d6a6dfbdc5c930dd626891a30e2da4/notebook-6.1.1-py3-none-any.whl (9.4MB)
    100% |████████████████████████████████| 9.4MB 4.1MB/s 
Collecting pyzmq>=13 (from jupyter-client->ipykernel>=5.1.2; python_version >= "3.4"->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/9e/fd/dcebddd29df55fa951144da02057aa2b1c521a5abcf37e811dc093f6f03d/pyzmq-19.0.2-cp36-cp36m-macosx_10_9_intel.whl (1.4MB)
    100% |████████████████████████████████| 1.4MB 17.6MB/s 
Collecting parso<0.8.0,>=0.7.0 (from jedi>=0.10->ipython>=4.0.0; python_version >= "3.3"->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/93/d1/e635bdde32890db5aeb2ffbde17e74f68986305a4466b0aa373b861e3f00/parso-0.7.1-py2.py3-none-any.whl (109kB)
    100% |████████████████████████████████| 112kB 8.7MB/s 
Collecting ptyprocess>=0.5 (from pexpect; sys_platform != "win32"->ipython>=4.0.0; python_version >= "3.3"->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/d1/29/605c2cc68a9992d18dada28206eeada56ea4bd07a239669da41674648b6f/ptyprocess-0.6.0-py2.py3-none-any.whl
Collecting wcwidth (from prompt-toolkit!=3.0.0,!=3.0.1,<3.1.0,>=2.0.0->ipython>=4.0.0; python_version >= "3.3"->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/59/7c/e39aca596badaf1b78e8f547c807b04dae603a433d3e7a7e04d67f2ef3e5/wcwidth-0.2.5-py2.py3-none-any.whl
Collecting argon2-cffi (from notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/74/fd/d78e003a79c453e8454197092fce9d1c6099445b7e7da0b04eb4fe1dbab7/argon2-cffi-20.1.0.tar.gz (1.8MB)
    100% |████████████████████████████████| 1.8MB 13.7MB/s 
  Installing build dependencies ... done
Collecting nbconvert (from notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/79/6c/05a569e9f703d18aacb89b7ad6075b404e8a4afde2c26b73ca77bb644b14/nbconvert-5.6.1-py2.py3-none-any.whl (455kB)
    100% |████████████████████████████████| 460kB 21.6MB/s 
Collecting Send2Trash (from notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/49/46/c3dc27481d1cc57b9385aff41c474ceb7714f7935b1247194adae45db714/Send2Trash-1.5.0-py3-none-any.whl
Collecting terminado>=0.8.3 (from notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/ff/96/1d9a2c23990aea8f8e0b5c3b6627d03196a73771a17a2d9860bbe9823ab6/terminado-0.8.3-py2.py3-none-any.whl
Collecting prometheus-client (from notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/3f/0e/554a265ffdc56e1494ef08e18f765b0cdec78797f510c58c45cf37abb4f4/prometheus_client-0.8.0-py2.py3-none-any.whl (53kB)
    100% |████████████████████████████████| 61kB 19.4MB/s 
Collecting cffi>=1.0.0 (from argon2-cffi->notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/9d/d3/f64f07d0110481ff20c2825711ec5d8b3c47a144ef4887dbd60872a56543/cffi-1.14.1-cp36-cp36m-macosx_10_9_x86_64.whl (175kB)
    100% |████████████████████████████████| 184kB 21.7MB/s 
Collecting bleach (from nbconvert->notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/9a/1e/7d6cb3b27cd2c490558349ca5d5cc05b390b017da1c704cac807ac8bd9fb/bleach-3.1.5-py2.py3-none-any.whl (151kB)
    100% |████████████████████████████████| 153kB 20.3MB/s 
Collecting testpath (from nbconvert->notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/1b/9e/1a170feaa54f22aeb5a5d16c9015e82234275a3c8ab630b552493f9cb8a9/testpath-0.4.4-py2.py3-none-any.whl (163kB)
    100% |████████████████████████████████| 174kB 24.5MB/s 
Collecting mistune<2,>=0.8.1 (from nbconvert->notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/09/ec/4b43dae793655b7d8a25f76119624350b4d65eb663459eb9603d7f1f0345/mistune-0.8.4-py2.py3-none-any.whl
Collecting pandocfilters>=1.4.1 (from nbconvert->notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/4c/ea/236e2584af67bb6df960832731a6e5325fd4441de001767da328c33368ce/pandocfilters-1.4.2.tar.gz
Collecting defusedxml (from nbconvert->notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/06/74/9b387472866358ebc08732de3da6dc48e44b0aacd2ddaa5cb85ab7e986a2/defusedxml-0.6.0-py2.py3-none-any.whl
Collecting pycparser (from cffi>=1.0.0->argon2-cffi->notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/ae/e7/d9c3a176ca4b02024debf82342dab36efadfc5776f9c8db077e8f6e71821/pycparser-2.20-py2.py3-none-any.whl (112kB)
    100% |████████████████████████████████| 112kB 15.1MB/s 
Collecting webencodings (from bleach->nbconvert->notebook>=4.4.1->widgetsnbextension~=3.5.0->ipywidgets>=7.0.0->pydeck>=0.1.dev5->streamlit)
  Downloading https://files.pythonhosted.org/packages/f4/24/2a3e3df732393fed8b3ebf2ec078f05546de641fe1b667ee316ec1dcf3b7/webencodings-0.5.1-py2.py3-none-any.whl
Installing collected packages: toml, tzlocal, watchdog, base58, ipython-genutils, traitlets, jupyter-core, nbformat, backcall, pickleshare, parso, jedi, appnope, ptyprocess, pexpect, wcwidth, prompt-toolkit, pygments, ipython, pyzmq, jupyter-client, ipykernel, pycparser, cffi, argon2-cffi, webencodings, bleach, testpath, mistune, pandocfilters, defusedxml, nbconvert, Send2Trash, terminado, prometheus-client, notebook, widgetsnbextension, ipywidgets, pydeck, enum-compat, pillow, streamlit
  Running setup.py install for watchdog ... error
    Complete output from command /Users/sean/Documents/mystuff/projects/streamlit_research/bin/python -u -c "import setuptools, tokenize;__file__='/private/tmp/pip-install-trhxw206/watchdog/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /private/tmp/pip-record-d3b9e4v5/install-record.txt --single-version-externally-managed --compile --install-headers /Users/sean/Documents/mystuff/projects/streamlit_research/include/site/python3.6/watchdog:
    running install
    running build
    running build_py
    creating build
    creating build/lib.macosx-10.14-x86_64-3.6
    creating build/lib.macosx-10.14-x86_64-3.6/watchdog
    copying src/watchdog/watchmedo.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog
    copying src/watchdog/version.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog
    copying src/watchdog/events.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog
    copying src/watchdog/__init__.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog
    creating build/lib.macosx-10.14-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/unicode_paths.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/compat.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/win32stat.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/__init__.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/dirsnapshot.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/delayed_queue.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/platform.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/bricks.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/utils
    copying src/watchdog/utils/echo.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/utils
    creating build/lib.macosx-10.14-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/fsevents.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/inotify.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/__init__.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/api.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/inotify_buffer.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/winapi.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/read_directory_changes.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/kqueue.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/inotify_c.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/polling.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/observers
    copying src/watchdog/observers/fsevents2.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/observers
    creating build/lib.macosx-10.14-x86_64-3.6/watchdog/tricks
    copying src/watchdog/tricks/__init__.py -> build/lib.macosx-10.14-x86_64-3.6/watchdog/tricks
    running egg_info
    writing src/watchdog.egg-info/PKG-INFO
    writing dependency_links to src/watchdog.egg-info/dependency_links.txt
    writing entry points to src/watchdog.egg-info/entry_points.txt
    writing requirements to src/watchdog.egg-info/requires.txt
    writing top-level names to src/watchdog.egg-info/top_level.txt
    reading manifest file 'src/watchdog.egg-info/SOURCES.txt'
    reading manifest template 'MANIFEST.in'
    warning: no files found matching '*.h' under directory 'src'
    writing manifest file 'src/watchdog.egg-info/SOURCES.txt'
    running build_ext
    building '_watchdog_fsevents' extension
    creating build/temp.macosx-10.14-x86_64-3.6
    creating build/temp.macosx-10.14-x86_64-3.6/src
    clang -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include -DWATCHDOG_VERSION_STRING="0.10.3" -DWATCHDOG_VERSION_MAJOR=0 -DWATCHDOG_VERSION_MINOR=10 -DWATCHDOG_VERSION_BUILD=3 -I/Users/sean/Documents/mystuff/projects/streamlit_research/include -I/Users/sean/.pyenv/versions/3.6.9/include/python3.6m -c src/watchdog_fsevents.c -o build/temp.macosx-10.14-x86_64-3.6/src/watchdog_fsevents.o -std=c99 -pedantic -Wall -Wextra -fPIC -Wno-nullability-completeness -Wno-nullability-extension -Wno-newline-eof -Wno-error=unused-command-line-argument
    clang: error: unable to execute command: Segmentation fault: 11
    clang: error: clang frontend command failed due to signal (use -v to see invocation)
    Apple clang version 11.0.0 (clang-1100.0.33.8)
    Target: x86_64-apple-darwin18.7.0
    Thread model: posix
    InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
    clang: note: diagnostic msg: PLEASE submit a bug report to http://developer.apple.com/bugreporter/ and include the crash backtrace, preprocessed source, and associated run script.
    clang: note: diagnostic msg:

``
We're still looking into this, but nobody here has been able to repro it yet :/ 

However: @sean-mcmann, it looks like your issue is actually subtly different than the others, in that `clang` is actually _crashing_ while trying to compile the watchdog lib (rather than failing with a compile error).

(I don't have a solution, just wanted to flag that there are potentially multiple issues being discussed.)
I was facing the same issue and the fix from [here](https://github.com/gorakhargosh/watchdog/issues/628#issuecomment-581480649) (as mentioned above) worked for me!

```
rm -rf /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk
```
if you have your own gcc install (find out by running `which gcc`) then pip uses it to compile watchdog which doesn't work even if you have Xcode tools installed. In that case, just temporarily move gcc somewhere and re run `pip install streamlit`
Hello @zack-klein! Do we have to install the 10.14 SDK again or does Mojave runs fine even without it?
use pipenv for virtual environment instead..
I had the same problem!
Try the following :
pip install --upgrade pip setuptools wheel

after that 

pip install streamlite
Just got this trying `pip3 install streamlit` on a Big Sur upgraded Macbook:

```
  ERROR: Command errored out with exit status 1:
   command: /usr/local/opt/python@3.8/bin/python3.8 -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/j_/n3lvr0j54kb8lk51slfjl3x80000gn/T/pip-install-my96lfwu/watchdog/setup.py'"'"'; __file__='"'"'/private/var/folders/j_/n3lvr0j54kb8lk51slfjl3x80000gn/T/pip-install-my96lfwu/watchdog/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' bdist_wheel -d /private/var/folders/j_/n3lvr0j54kb8lk51slfjl3x80000gn/T/pip-wheel-34wcnp3p
       cwd: /private/var/folders/j_/n3lvr0j54kb8lk51slfjl3x80000gn/T/pip-install-my96lfwu/watchdog/
  Complete output (49 lines):
  running bdist_wheel
  running build
  running build_py
  creating build
  creating build/lib.macosx-10.15-x86_64-3.8
  creating build/lib.macosx-10.15-x86_64-3.8/watchdog
  copying src/watchdog/watchmedo.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog
  copying src/watchdog/version.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog
  copying src/watchdog/events.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog
  copying src/watchdog/__init__.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog
  creating build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
  copying src/watchdog/utils/patterns.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
  copying src/watchdog/utils/__init__.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
  copying src/watchdog/utils/dirsnapshot.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
  copying src/watchdog/utils/delayed_queue.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
  copying src/watchdog/utils/platform.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
  copying src/watchdog/utils/bricks.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
  copying src/watchdog/utils/echo.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
  creating build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
  copying src/watchdog/observers/fsevents.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
  copying src/watchdog/observers/inotify.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
  copying src/watchdog/observers/__init__.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
  copying src/watchdog/observers/api.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
  copying src/watchdog/observers/inotify_buffer.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
  copying src/watchdog/observers/winapi.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
  copying src/watchdog/observers/read_directory_changes.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
  copying src/watchdog/observers/kqueue.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
  copying src/watchdog/observers/inotify_c.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
  copying src/watchdog/observers/polling.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
  copying src/watchdog/observers/fsevents2.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
  creating build/lib.macosx-10.15-x86_64-3.8/watchdog/tricks
  copying src/watchdog/tricks/__init__.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/tricks
  running egg_info
  writing src/watchdog.egg-info/PKG-INFO
  writing dependency_links to src/watchdog.egg-info/dependency_links.txt
  writing entry points to src/watchdog.egg-info/entry_points.txt
  writing requirements to src/watchdog.egg-info/requires.txt
  writing top-level names to src/watchdog.egg-info/top_level.txt
  reading manifest file 'src/watchdog.egg-info/SOURCES.txt'
  reading manifest template 'MANIFEST.in'
  warning: no files found matching '*.h' under directory 'src'
  writing manifest file 'src/watchdog.egg-info/SOURCES.txt'
  running build_ext
  building '_watchdog_fsevents' extension
  creating build/temp.macosx-10.15-x86_64-3.8
  creating build/temp.macosx-10.15-x86_64-3.8/src
  clang -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/usr/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Tk.framework/Versions/8.5/Headers -DWATCHDOG_VERSION_STRING="1.0.1" -DWATCHDOG_VERSION_MAJOR=1 -DWATCHDOG_VERSION_MINOR=0 -DWATCHDOG_VERSION_BUILD=1 -I/usr/local/include -I/usr/local/opt/openssl@1.1/include -I/usr/local/opt/sqlite/include -I/usr/local/Cellar/python@3.8/3.8.5/Frameworks/Python.framework/Versions/3.8/include/python3.8 -c src/watchdog_fsevents.c -o build/temp.macosx-10.15-x86_64-3.8/src/watchdog_fsevents.o -std=c99 -pedantic -Wall -Wextra -fPIC -Wno-nullability-completeness -Wno-nullability-extension -Wno-newline-eof -Wno-error=unused-command-line-argument
  xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
  error: command 'clang' failed with exit status 1
  ----------------------------------------
  ERROR: Failed building wheel for watchdog
  Running setup.py clean for watchdog
Failed to build watchdog
Installing collected packages: smmap, gitdb, gitpython, astor, chardet, idna, urllib3, certifi, requests, tornado, python-dateutil, pandas, blinker, decorator, validators, cachetools, pyparsing, packaging, pyzmq, ipython-genutils, traitlets, jupyter-core, jupyter-client, appnope, pickleshare, ptyprocess, pexpect, parso, jedi, wcwidth, prompt-toolkit, pygments, backcall, ipython, ipykernel, Send2Trash, attrs, pyrsistent, jsonschema, nbformat, prometheus-client, pycparser, cffi, argon2-cffi, terminado, webencodings, bleach, pandocfilters, jupyterlab-pygments, MarkupSafe, jinja2, defusedxml, testpath, entrypoints, nest-asyncio, async-generator, nbclient, mistune, nbconvert, notebook, widgetsnbextension, ipywidgets, pydeck, toolz, altair, watchdog, base58, streamlit
    Running setup.py install for watchdog ... error
    ERROR: Command errored out with exit status 1:
     command: /usr/local/opt/python@3.8/bin/python3.8 -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/j_/n3lvr0j54kb8lk51slfjl3x80000gn/T/pip-install-my96lfwu/watchdog/setup.py'"'"'; __file__='"'"'/private/var/folders/j_/n3lvr0j54kb8lk51slfjl3x80000gn/T/pip-install-my96lfwu/watchdog/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /private/var/folders/j_/n3lvr0j54kb8lk51slfjl3x80000gn/T/pip-record-jm_lq0ee/install-record.txt --single-version-externally-managed --compile --install-headers /usr/local/include/python3.8/watchdog
         cwd: /private/var/folders/j_/n3lvr0j54kb8lk51slfjl3x80000gn/T/pip-install-my96lfwu/watchdog/
    Complete output (49 lines):
    running install
    running build
    running build_py
    creating build
    creating build/lib.macosx-10.15-x86_64-3.8
    creating build/lib.macosx-10.15-x86_64-3.8/watchdog
    copying src/watchdog/watchmedo.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog
    copying src/watchdog/version.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog
    copying src/watchdog/events.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog
    copying src/watchdog/__init__.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog
    creating build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
    copying src/watchdog/utils/patterns.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
    copying src/watchdog/utils/__init__.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
    copying src/watchdog/utils/dirsnapshot.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
    copying src/watchdog/utils/delayed_queue.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
    copying src/watchdog/utils/platform.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
    copying src/watchdog/utils/bricks.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
    copying src/watchdog/utils/echo.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/utils
    creating build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
    copying src/watchdog/observers/fsevents.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
    copying src/watchdog/observers/inotify.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
    copying src/watchdog/observers/__init__.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
    copying src/watchdog/observers/api.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
    copying src/watchdog/observers/inotify_buffer.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
    copying src/watchdog/observers/winapi.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
    copying src/watchdog/observers/read_directory_changes.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
    copying src/watchdog/observers/kqueue.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
    copying src/watchdog/observers/inotify_c.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
    copying src/watchdog/observers/polling.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
    copying src/watchdog/observers/fsevents2.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/observers
    creating build/lib.macosx-10.15-x86_64-3.8/watchdog/tricks
    copying src/watchdog/tricks/__init__.py -> build/lib.macosx-10.15-x86_64-3.8/watchdog/tricks
    running egg_info
    writing src/watchdog.egg-info/PKG-INFO
    writing dependency_links to src/watchdog.egg-info/dependency_links.txt
    writing entry points to src/watchdog.egg-info/entry_points.txt
    writing requirements to src/watchdog.egg-info/requires.txt
    writing top-level names to src/watchdog.egg-info/top_level.txt
    reading manifest file 'src/watchdog.egg-info/SOURCES.txt'
    reading manifest template 'MANIFEST.in'
    warning: no files found matching '*.h' under directory 'src'
    writing manifest file 'src/watchdog.egg-info/SOURCES.txt'
    running build_ext
    building '_watchdog_fsevents' extension
    creating build/temp.macosx-10.15-x86_64-3.8
    creating build/temp.macosx-10.15-x86_64-3.8/src
    clang -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/usr/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Tk.framework/Versions/8.5/Headers -DWATCHDOG_VERSION_STRING="1.0.1" -DWATCHDOG_VERSION_MAJOR=1 -DWATCHDOG_VERSION_MINOR=0 -DWATCHDOG_VERSION_BUILD=1 -I/usr/local/include -I/usr/local/opt/openssl@1.1/include -I/usr/local/opt/sqlite/include -I/usr/local/Cellar/python@3.8/3.8.5/Frameworks/Python.framework/Versions/3.8/include/python3.8 -c src/watchdog_fsevents.c -o build/temp.macosx-10.15-x86_64-3.8/src/watchdog_fsevents.o -std=c99 -pedantic -Wall -Wextra -fPIC -Wno-nullability-completeness -Wno-nullability-extension -Wno-newline-eof -Wno-error=unused-command-line-argument
    xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
    error: command 'clang' failed with exit status 1
    ----------------------------------------
ERROR: Command errored out with exit status 1: /usr/local/opt/python@3.8/bin/python3.8 -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/j_/n3lvr0j54kb8lk51slfjl3x80000gn/T/pip-install-my96lfwu/watchdog/setup.py'"'"'; __file__='"'"'/private/var/folders/j_/n3lvr0j54kb8lk51slfjl3x80000gn/T/pip-install-my96lfwu/watchdog/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /private/var/folders/j_/n3lvr0j54kb8lk51slfjl3x80000gn/T/pip-record-jm_lq0ee/install-record.txt --single-version-externally-managed --compile --install-headers /usr/local/include/python3.8/watchdog Check the logs for full command output.
```

Resolving patch:
diff --git a/lib/setup.py b/lib/setup.py
--- a/lib/setup.py
+++ b/lib/setup.py
@@ -1,7 +1,5 @@
 import os
-import platform
 import setuptools
-import subprocess
 import sys
 
 from setuptools.command.install import install
@@ -33,18 +31,6 @@
 packages = pipfile["packages"].copy()
 requirements = convert_deps_to_pip(packages, r=False)
 
-# Check whether xcode tools are available before making watchdog a
-# dependency (only if the current system is a Mac).
-if platform.system() == "Darwin":
-    has_xcode = subprocess.call(["xcode-select", "--version"], shell=False) == 0
-    has_gcc = subprocess.call(["gcc", "--version"], shell=False) == 0
-
-    if not (has_xcode and has_gcc):
-        try:
-            requirements.remove("watchdog")
-        except ValueError:
-            pass
-
 
 class VerifyVersionCommand(install):
     """Custom command to verify that the git tag matches our version"""


Test patch: