Repository: pyca/cryptography

Issue:
Stop importing distutils in setup.py?
This warning is present in our CI:


> /home/travis/build/pyca/cryptography/.tox/packaging/lib/python3.8/site-packages/setuptools/distutils_patch.py:25: UserWarning: Distutils was imported before Setuptools. This usage is discouraged and may exhibit undesirable behaviors or errors. Please use Setuptools' objects directly or at least import Setuptools first.

It is being triggered by our import in `setup.py`:

https://github.com/pyca/cryptography/blob/9e84c88ad3c5bf8b404fe86e22bdadd6b56e58ec/setup.py#L12

If we don't need this we probably should stop doing it.


Discussion:
`build` doesn't exist in `setuptools`, so AFAICT we can't just change that import path.

The simplest fix is probably just to move that import down.

The other fix would be to remove the thingy in setup.py that all this exists for, the wacky argument parsing. I think maybe it's time.
Putting this in milestone pending learning whether our experiment removing the keywords with side effects code on bcrypt is successful.
> This warning is present in our CI:
> 
> > /home/travis/build/pyca/cryptography/.tox/packaging/lib/python3.8/site-packages/setuptools/distutils_patch.py:25: UserWarning: Distutils was imported before Setuptools. This usage is discouraged and may exhibit undesirable behaviors or errors. Please use Setuptools' objects directly or at least import Setuptools first.
> 
> It is being triggered by our import in `setup.py`:
> 
> https://github.com/pyca/cryptography/blob/9e84c88ad3c5bf8b404fe86e22bdadd6b56e58ec/setup.py#L12
> 
> If we don't need this we probably should stop doing it.

Try this pip install setuptools packagename

Resolving patch:
diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -9,13 +9,11 @@
 import os
 import platform
 import sys
-from distutils.command.build import build
 
 import pkg_resources
 
 import setuptools
 from setuptools import find_packages, setup
-from setuptools.command.install import install
 
 
 if pkg_resources.parse_version(
@@ -49,145 +47,6 @@
         )
 
 
-def keywords_with_side_effects(argv):
-    """
-    Get a dictionary with setup keywords that (can) have side effects.
-
-    :param argv: A list of strings with command line arguments.
-    :returns: A dictionary with keyword arguments for the ``setup()`` function.
-
-    This setup.py script uses the setuptools 'setup_requires' feature because
-    this is required by the cffi package to compile extension modules. The
-    purpose of ``keywords_with_side_effects()`` is to avoid triggering the cffi
-    build process as a result of setup.py invocations that don't need the cffi
-    module to be built (setup.py serves the dual purpose of exposing package
-    metadata).
-
-    All of the options listed by ``python setup.py --help`` that print
-    information should be recognized here. The commands ``clean``,
-    ``egg_info``, ``register``, ``sdist`` and ``upload`` are also recognized.
-    Any combination of these options and commands is also supported.
-
-    This function was originally based on the `setup.py script`_ of SciPy (see
-    also the discussion in `pip issue #25`_).
-
-    .. _pip issue #25: https://github.com/pypa/pip/issues/25
-    .. _setup.py script: https://github.com/scipy/scipy/blob/master/setup.py
-    """
-    no_setup_requires_arguments = (
-        "-h",
-        "--help",
-        "-n",
-        "--dry-run",
-        "-q",
-        "--quiet",
-        "-v",
-        "--verbose",
-        "-V",
-        "--version",
-        "--author",
-        "--author-email",
-        "--classifiers",
-        "--contact",
-        "--contact-email",
-        "--description",
-        "--egg-base",
-        "--fullname",
-        "--help-commands",
-        "--keywords",
-        "--licence",
-        "--license",
-        "--long-description",
-        "--maintainer",
-        "--maintainer-email",
-        "--name",
-        "--no-user-cfg",
-        "--obsoletes",
-        "--platforms",
-        "--provides",
-        "--requires",
-        "--url",
-        "clean",
-        "egg_info",
-        "register",
-        "sdist",
-        "upload",
-    )
-
-    def is_short_option(argument):
-        """Check whether a command line argument is a short option."""
-        return len(argument) >= 2 and argument[0] == "-" and argument[1] != "-"
-
-    def expand_short_options(argument):
-        """Expand combined short options into canonical short options."""
-        return ("-" + char for char in argument[1:])
-
-    def argument_without_setup_requirements(argv, i):
-        """Check whether a command line argument needs setup requirements."""
-        if argv[i] in no_setup_requires_arguments:
-            # Simple case: An argument which is either an option or a command
-            # which doesn't need setup requirements.
-            return True
-        elif is_short_option(argv[i]) and all(
-            option in no_setup_requires_arguments
-            for option in expand_short_options(argv[i])
-        ):
-            # Not so simple case: Combined short options none of which need
-            # setup requirements.
-            return True
-        elif argv[i - 1 : i] == ["--egg-base"]:
-            # Tricky case: --egg-info takes an argument which should not make
-            # us use setup_requires (defeating the purpose of this code).
-            return True
-        else:
-            return False
-
-    if all(
-        argument_without_setup_requirements(argv, i)
-        for i in range(1, len(argv))
-    ):
-        return {"cmdclass": {"build": DummyBuild, "install": DummyInstall}}
-    else:
-        cffi_modules = [
-            "src/_cffi_src/build_openssl.py:ffi",
-            "src/_cffi_src/build_padding.py:ffi",
-        ]
-
-        return {
-            "setup_requires": setup_requirements,
-            "cffi_modules": cffi_modules,
-        }
-
-
-setup_requires_error = (
-    "Requested setup command that needs 'setup_requires' "
-    "while command line arguments implied a side effect "
-    "free command or option."
-)
-
-
-class DummyBuild(build):
-    """
-    This class makes it very obvious when ``keywords_with_side_effects()`` has
-    incorrectly interpreted the command line arguments to ``setup.py build`` as
-    one of the 'side effect free' commands or options.
-    """
-
-    def run(self):
-        raise RuntimeError(setup_requires_error)
-
-
-class DummyInstall(install):
-    """
-    This class makes it very obvious when ``keywords_with_side_effects()`` has
-    incorrectly interpreted the command line arguments to ``setup.py install``
-    as one of the 'side effect free' commands or options.
-    """
-
-    def run(self):
-        raise RuntimeError(setup_requires_error)
-
-
 with open(os.path.join(base_dir, "README.rst")) as f:
     long_description = f.read()
 
@@ -230,6 +89,7 @@ def run(self):
     include_package_data=True,
     python_requires=">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*",
     install_requires=["six >= 1.4.1"] + setup_requirements,
+    setup_requires=setup_requirements,
     extras_require={
         ":python_version < '3'": ["enum34", "ipaddress"],
         "test": [
@@ -257,5 +117,8 @@ def run(self):
     # for cffi
     zip_safe=False,
     ext_package="cryptography.hazmat.bindings",
-    **keywords_with_side_effects(sys.argv)
+    cffi_modules=[
+        "src/_cffi_src/build_openssl.py:ffi",
+        "src/_cffi_src/build_padding.py:ffi",
+    ],
 )


Test patch: