Issue 1:
Hello.

I am trying to install matplotlib on MacOS Catalina (version 10.15.6) and Python 3.9 with this command:

pip3 install matplotlib

But I get this long error:

`pip3 install matplotlib

Collecting matplotlib

Using cached matplotlib-3.3.2.tar.gz (37.9 MB)

ERROR: Command errored out with exit status 1:

command: /Library/Frameworks/Python.framework/Versions/3.9/bin/python3.9 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-install-e4h4p2_1/matplotlib/setup.py'"'"'; file='"'"'/private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-install-e4h4p2_1/matplotlib/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(file);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, file, '"'"'exec'"'"'))' egg_info --egg-base /private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-pip-egg-info-tan2fixa

cwd: /private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-install-e4h4p2_1/matplotlib/

Complete output (62 lines):

Edit setup.cfg to change the build options; suppress output with --quiet.

BUILDING MATPLOTLIB
matplotlib: yes [3.3.2]
python: yes [3.9.0 (v3.9.0:9cf6752276, Oct 5 2020, 11:29:23) [Clang 6.0
(clang-600.0.57)]]
platform: yes [darwin]
sample_data: yes [installing]
tests: no [skipping due to configuration]
macosx: yes [installing]

running egg_info
creating /private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-pip-egg-info-tan2fixa/matplotlib.egg-info
writing /private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-pip-egg-info-tan2fixa/matplotlib.egg-info/PKG-INFO
writing dependency_links to /private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-pip-egg-info-tan2fixa/matplotlib.egg-info/dependency_links.txt
writing namespace_packages to /private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-pip-egg-info-tan2fixa/matplotlib.egg-info/namespace_packages.txt
writing requirements to /private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-pip-egg-info-tan2fixa/matplotlib.egg-info/requires.txt
writing top-level names to /private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-pip-egg-info-tan2fixa/matplotlib.egg-info/top_level.txt
writing manifest file '/private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-pip-egg-info-tan2fixa/matplotlib.egg-info/SOURCES.txt'
init_dgelsd failed init
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-install-e4h4p2_1/matplotlib/setup.py", line 242, in <module>
setup( # Finally, pass this all along to distutils to do the heavy lifting.
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/setuptools/__init__.py", line 153, in setup
return distutils.core.setup(**attrs)
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/core.py", line 148, in setup
dist.run_commands()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/dist.py", line 966, in run_commands
self.run_command(cmd)
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/dist.py", line 985, in run_command
cmd_obj.run()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 298, in run
self.find_sources()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 305, in find_sources
mm.run()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 536, in run
self.add_defaults()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 572, in add_defaults
sdist.add_defaults(self)
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/command/sdist.py", line 228, in add_defaults
self._add_defaults_ext()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/command/sdist.py", line 311, in _add_defaults_ext
build_ext = self.get_finalized_command('build_ext')
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/cmd.py", line 299, in get_finalized_command
cmd_obj.ensure_finalized()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/cmd.py", line 107, in ensure_finalized
self.finalize_options()
File "/private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-install-e4h4p2_1/matplotlib/setup.py", line 88, in finalize_options
self.distribution.ext_modules[:] = [
File "/private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-install-e4h4p2_1/matplotlib/setup.py", line 91, in <listcomp>
for ext in package.get_extensions()
File "/private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-install-e4h4p2_1/matplotlib/setupext.py", line 345, in get_extensions
add_numpy_flags(ext)
File "/private/var/folders/20/l7ql06pw8xjf_x0059b44jsh0000gq/T/pip-install-e4h4p2_1/matplotlib/setupext.py", line 469, in add_numpy_flags
import numpy as np
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/numpy/__init__.py", line 286, in <module>
raise RuntimeError(msg)
RuntimeError: Polyfit sanity test emitted a warning, most likely due to using a buggy Accelerate backend. If you compiled yourself, see site.cfg.example for information. Otherwise report this to the vendor that provided NumPy.
RankWarning: Polyfit may be poorly conditioned

----------------------------------------

ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

`

Any ideas?

Thanks to anyone in advance.

All the best,

Fab.

Issue 2:
Collecting matplotlib

Using cached matplotlib-3.3.2.tar.gz (37.9 MB)

ERROR: Command errored out with exit status 1:

command: /Library/Frameworks/Python.framework/Versions/3.9/bin/python3.9 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-install-p_zq0z2f/matplotlib/setup.py'"'"'; file='"'"'/private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-install-p_zq0z2f/matplotlib/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(file);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, file, '"'"'exec'"'"'))' egg_info --egg-base /private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-pip-egg-info-aq680rqr

cwd: /private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-install-p_zq0z2f/matplotlib/

Complete output (63 lines):

WARNING: The wheel package is not available.

Edit setup.cfg to change the build options; suppress output with --quiet.

BUILDING MATPLOTLIB
matplotlib: yes [3.3.2]
python: yes [3.9.0 (v3.9.0:9cf6752276, Oct 5 2020, 11:29:23) [Clang 6.0
(clang-600.0.57)]]
platform: yes [darwin]
sample_data: yes [installing]
tests: no [skipping due to configuration]
macosx: yes [installing]

running egg_info
creating /private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-pip-egg-info-aq680rqr/matplotlib.egg-info
writing /private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-pip-egg-info-aq680rqr/matplotlib.egg-info/PKG-INFO
writing dependency_links to /private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-pip-egg-info-aq680rqr/matplotlib.egg-info/dependency_links.txt
writing namespace_packages to /private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-pip-egg-info-aq680rqr/matplotlib.egg-info/namespace_packages.txt
writing requirements to /private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-pip-egg-info-aq680rqr/matplotlib.egg-info/requires.txt
writing top-level names to /private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-pip-egg-info-aq680rqr/matplotlib.egg-info/top_level.txt
writing manifest file '/private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-pip-egg-info-aq680rqr/matplotlib.egg-info/SOURCES.txt'
init_dgelsd failed init
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-install-p_zq0z2f/matplotlib/setup.py", line 242, in <module>
setup( # Finally, pass this all along to distutils to do the heavy lifting.
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/setuptools/__init__.py", line 165, in setup
return distutils.core.setup(**attrs)
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/core.py", line 148, in setup
dist.run_commands()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/dist.py", line 966, in run_commands
self.run_command(cmd)
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/dist.py", line 985, in run_command
cmd_obj.run()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 297, in run
self.find_sources()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 304, in find_sources
mm.run()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 535, in run
self.add_defaults()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 571, in add_defaults
sdist.add_defaults(self)
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/command/sdist.py", line 228, in add_defaults
self._add_defaults_ext()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/command/sdist.py", line 311, in _add_defaults_ext
build_ext = self.get_finalized_command('build_ext')
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/cmd.py", line 299, in get_finalized_command
cmd_obj.ensure_finalized()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/cmd.py", line 107, in ensure_finalized
self.finalize_options()
File "/private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-install-p_zq0z2f/matplotlib/setup.py", line 88, in finalize_options
self.distribution.ext_modules[:] = [
File "/private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-install-p_zq0z2f/matplotlib/setup.py", line 91, in <listcomp>
for ext in package.get_extensions()
File "/private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-install-p_zq0z2f/matplotlib/setupext.py", line 345, in get_extensions
add_numpy_flags(ext)
File "/private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-install-p_zq0z2f/matplotlib/setupext.py", line 469, in add_numpy_flags
import numpy as np
File "/private/var/folders/_b/73g4h5qs7qv51ctyl5tby0040000gn/T/pip-install-p_zq0z2f/matplotlib/.eggs/numpy-1.19.2-py3.9-macosx-10.9-x86_64.egg/numpy/__init__.py", line 286, in <module>
raise RuntimeError(msg)
RuntimeError: Polyfit sanity test emitted a warning, most likely due to using a buggy Accelerate backend. If you compiled yourself, see site.cfg.example for information. Otherwise report this to the vendor that provided NumPy.
RankWarning: Polyfit may be poorly conditioned

----------------------------------------

ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.