PYTHON-3760 Add C extension building as part of tox test environment

[blink1073]

Fails as expected when the c extension has an error now:

      gcc -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -arch x86_64 -g -Ibson -I/Users/steve.silvester/workspace/mongo-python-driver/.tox/test/include -I/Library/Frameworks/Python.framework/Versions/3.7/include/python3.7m -c bson/_cbsonmodule.c -o build/temp.macosx-10.9-x86_64-cpython-37/bson/_cbsonmodule.o
      bson/_cbsonmodule.c:282:5: error: use of undeclared identifier 'a'
          a = b;
          ^
      bson/_cbsonmodule.c:282:9: error: use of undeclared identifier 'b'
          a = b;
              ^
      2 errors generated.
      /private/tmp/pip-build-env-4cfbi019/overlay/lib/python3.7/site-packages/setuptools/config/pyprojecttoml.py:66: _BetaConfiguration: Support for `[tool.setuptools]` in `pyproject.toml` is still *beta*.
        config = read_configuration(filepath, True, ignore_option_errors, dist)
      error: command '/usr/bin/gcc' failed with exit code 1
      [end of output]

  note: This error originates from a subprocess, and is likely not a problem with pip.
  ERROR: Failed building wheel for pymongo
ERROR: Could not build wheels for pymongo, which is required to install pyproject.toml-based projects

test: exit 1 (4.24 seconds) /Users/steve.silvester/workspace/mongo-python-driver> python -I -m pip install --force-reinstall --no-deps /Users/steve.silvester/workspace/mongo-python-driver/.tox/.tmp/package/9/pymongo-4.5.0.dev0.tar.gz pid=44837
.pkg: _exit> python /Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pyproject_api/_backend.py True setuptools.build_meta
  test: FAIL code 1 (5.28 seconds)
  evaluation failed :( (5.36 seconds)

[ShaneHarvey]

Will this work when running with pypy? edit: I see the pypy tests are passing.

[casch-at]

Unfortunately this brakes installing pymongo within a tox environment where gcc is not available. I guess, I need to set the NO_EXT environment then?

EDIT:
Setting NO_EXT leads to different version, last working version is 4.4.1

$ export NO_EXT=1
$ pip install pymongo

Collecting pymongo
  Downloading https://pypi.sozvers.at/root/pypi/%2Bf/681/f252e43b3ef05/pymongo-4.5.0.tar.gz (848 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 848.7/848.7 kB 13.9 MB/s eta 0:00:00
  Installing build dependencies ... done
  Getting requirements to build wheel ... error
  error: subprocess-exited-with-error
  
  × Getting requirements to build wheel did not run successfully.
  │ exit code: 1
  ╰─> [18 lines of output]
      Traceback (most recent call last):
        File "/usr/local/lib/python3.11/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 353, in <module>
          main()
        File "/usr/local/lib/python3.11/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 335, in main
          json_out['return_val'] = hook(**hook_input['kwargs'])
                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "/usr/local/lib/python3.11/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 118, in get_requires_for_build_wheel
          return hook(config_settings)
                 ^^^^^^^^^^^^^^^^^^^^^
        File "/tmp/pip-build-env-53sxbup9/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 355, in get_requires_for_build_wheel
          return self._get_build_requires(config_settings, requirements=['wheel'])
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "/tmp/pip-build-env-53sxbup9/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 325, in _get_build_requires
          self.run_setup()
        File "/tmp/pip-build-env-53sxbup9/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 341, in run_setup
          exec(code, locals())
        File "<string>", line 119, in <module>
      ValueError: list.remove(x): x not in list
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: subprocess-exited-with-error

× Getting requirements to build wheel did not run successfully.
│ exit code: 1
╰─> See above for output.

[ShaneHarvey]

@cslux Thank you for the report, we'll fix this in https://jira.mongodb.org/browse/PYTHON-3968

[ShaneHarvey]

I suspect the only workaround (until PYTHON-3968 is implemented) might be to temporarily unset the TOX_ENV_NAME var:

$ export _TOX_ENV_NAME=$TOX_ENV_NAME
$ unset TOX_ENV_NAME
$ pip install pymongo
$ export TOX_ENV_NAME=$_TOX_ENV_NAME
$ unset _TOX_ENV_NAME