Install does not respect `PIP_NO_BUILD_ISOLATION`

Description

In a new venv, I can install friendly from trunk by using --no-build-isolation. This doesn’t hold if I export PIP_NO_BUILD_ISOLATION=1; looks like pip ignores the setting passed via env var.

Expected behavior

The behaviour of PIP_NO_BUILD_ISOLATION=1 pip install git+https://<url> should be the same as of pip install --no-build-isolation git+https://<url>, if I read Environment Variables correctly.

pip version

21.1.1

Python version

3.9.4

OS

Fedora 34

How to Reproduce

$ python -m venv tst
$ source tst/bin/activate
$ pip install --upgrade pip
$ pip install pygments rich pure_eval wheel  # install deps first
$ export PIP_NO_BUILD_ISOLATION=1
$ pip install git+https://github.com/aroberge/friendly@master

Output

Collecting git+https://github.com/aroberge/friendly@master
  Cloning https://github.com/aroberge/friendly (to revision master) to ./pip-req-build-4j8mp19r
  Running command git clone -q https://github.com/aroberge/friendly /tmp/pip-req-build-4j8mp19r
  Installing build dependencies ... done
  Getting requirements to build wheel ... error
  ERROR: Command errored out with exit status 1:
   command: /tmp/tst/bin/python /tmp/tst/lib64/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py get_requires_for_build_wheel /tmp/tmpqe9axa75
       cwd: /tmp/pip-req-build-4j8mp19r
  Complete output (70 lines):
  Traceback (most recent call last):
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/config.py", line 33, in __getattr__
      return next(
  StopIteration
  
  The above exception was the direct cause of the following exception:
  
  Traceback (most recent call last):
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/config.py", line 387, in _parse_attr
      return getattr(StaticModule(module_name), attr_name)
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/config.py", line 41, in __getattr__
      raise AttributeError(
  AttributeError: friendly has no attribute __version__
  
  During handling of the above exception, another exception occurred:
  
  Traceback (most recent call last):
    File "/tmp/tst/lib64/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 280, in <module>
      main()
    File "/tmp/tst/lib64/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 263, in main
      json_out['return_val'] = hook(**hook_input['kwargs'])
    File "/tmp/tst/lib64/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 114, in get_requires_for_build_wheel
      return hook(config_settings)
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/build_meta.py", line 154, in get_requires_for_build_wheel
      return self._get_build_requires(
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/build_meta.py", line 135, in _get_build_requires
      self.run_setup()
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/build_meta.py", line 150, in run_setup
      exec(compile(code, __file__, 'exec'), locals())
    File "setup.py", line 3, in <module>
      setup()
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/__init__.py", line 153, in setup
      return distutils.core.setup(**attrs)
    File "/usr/lib64/python3.9/distutils/core.py", line 121, in setup
      dist.parse_config_files()
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/dist.py", line 742, in parse_config_files
      parse_configuration(self, self.command_options,
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/config.py", line 157, in parse_configuration
      meta.parse()
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/config.py", line 463, in parse
      section_parser_method(section_options)
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/config.py", line 436, in parse_section
      self[name] = value
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/config.py", line 220, in __setitem__
      value = parser(value)
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/config.py", line 552, in _parse_version
      version = self._parse_attr(value, self.package_dir)
    File "/tmp/pip-build-env-ilxve4yd/overlay/lib/python3.9/site-packages/setuptools/config.py", line 390, in _parse_attr
      module = importlib.import_module(module_name)
    File "/usr/lib64/python3.9/importlib/__init__.py", line 127, in import_module
      return _bootstrap._gcd_import(name[level:], package, level)
    File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
    File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
    File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
    File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
    File "<frozen importlib._bootstrap_external>", line 790, in exec_module
    File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
    File "/tmp/pip-req-build-4j8mp19r/friendly/__init__.py", line 38, in <module>
      from . import editors_helpers
    File "/tmp/pip-req-build-4j8mp19r/friendly/editors_helpers.py", line 18, in <module>
      from .config import session
    File "/tmp/pip-req-build-4j8mp19r/friendly/config.py", line 7, in <module>
      from . import core
    File "/tmp/pip-req-build-4j8mp19r/friendly/core.py", line 19, in <module>
      from . import info_variables
    File "/tmp/pip-req-build-4j8mp19r/friendly/info_variables.py", line 10, in <module>
      from . import utils
    File "/tmp/pip-req-build-4j8mp19r/friendly/utils.py", line 9, in <module>
      import pure_eval
  ModuleNotFoundError: No module named 'pure_eval'
  ----------------------------------------
WARNING: Discarding git+https://github.com/aroberge/friendly@master. Command errored out with exit status 1: /tmp/tst/bin/python /tmp/tst/lib64/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py get_requires_for_build_wheel /tmp/tmpqe9axa75 Check the logs for full command output.
ERROR: Command errored out with exit status 1: /tmp/tst/bin/python /tmp/tst/lib64/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py get_requires_for_build_wheel /tmp/tmpqe9axa75 Check the logs for full command output.

Code of Conduct

• I agree to follow the PSF Code of Conduct.

[pfmoore]

@hoefling Apologies. I told you those “double-negative” command line options were weird. The value you need is PIP_NO_BUILD_ISOLATION=0 (note, set it to 0 not 1). The option is --no-build-isolation, so the variable is PIP_NO_BUILD_ISOLATION. But the action is store_false, so you need to set the variable to 0 to get the same effect as supplying the flag. Yes, we know this is stupid. It’s on the list of things to fix, under “use a different option parsing library” (which as you can imagine is a non-trivial job).

If you have any suggestions about how we could document this for people who hit it, a docs PR would be welcomed as a quick improvement for now.

❯ $env:PIP_NO_BUILD_ISOLATION=0
PS 09:22 (6b66ffab6edd6c) 00:00.016 C:\Work\Scratch\pypidata
❯ py -m pip install --no-build-isolation "git+https://github.com/aroberge/friendly@master"
Collecting git+https://github.com/aroberge/friendly@master
  Cloning https://github.com/aroberge/friendly (to revision master) to c:\users\uk03306\appdata\local\temp\pip-req-build-mtbrshwv
  Running command git clone -q https://github.com/aroberge/friendly 'C:\Users\UK03306\AppData\Local\Temp\pip-req-build-mtbrshwv'
    Preparing wheel metadata ... done
Collecting asttokens>=2.0.4
  Using cached asttokens-2.0.5-py2.py3-none-any.whl (20 kB)
Collecting executing>=0.5.3
  Using cached executing-0.6.0-py2.py3-none-any.whl (12 kB)
Requirement already satisfied: pygments>=2.6 in c:\users\uk03306\.virtualenvs\6b66ffab6edd6c\lib\site-packages (from friendly==0.3.46) (2.9.0)
Requirement already satisfied: rich>=9.12 in c:\users\uk03306\.virtualenvs\6b66ffab6edd6c\lib\site-packages (from friendly==0.3.46) (10.1.0)
Requirement already satisfied: pure-eval>=0.2.1 in c:\users\uk03306\.virtualenvs\6b66ffab6edd6c\lib\site-packages (from friendly==0.3.46) (0.2.1)
Collecting six
  Using cached six-1.16.0-py2.py3-none-any.whl (11 kB)
Requirement already satisfied: commonmark<0.10.0,>=0.9.0 in c:\users\uk03306\.virtualenvs\6b66ffab6edd6c\lib\site-packages (from rich>=9.12->friendly==0.3.46) (0.9.1)
Requirement already satisfied: typing-extensions<4.0.0,>=3.7.4 in c:\users\uk03306\.virtualenvs\6b66ffab6edd6c\lib\site-packages (from rich>=9.12->friendly==0.3.46) (3.10.0.0)
Requirement already satisfied: colorama<0.5.0,>=0.4.0 in c:\users\uk03306\.virtualenvs\6b66ffab6edd6c\lib\site-packages (from rich>=9.12->friendly==0.3.46) (0.4.4)
Building wheels for collected packages: friendly
  Building wheel for friendly (PEP 517) ... done
  Created wheel for friendly: filename=friendly-0.3.46-py3-none-any.whl size=213992 sha256=c39c27fb708a9fb7afc51da3735886e76e896ffe7c6dfa97d22bbcbd98837a1c
  Stored in directory: C:\Users\UK03306\AppData\Local\Temp\pip-ephem-wheel-cache-yy2qujxi\wheels\1b\9e\9a\37c39185ab58a858f558664960e816c71ccd2f07ba5079cc0d
Successfully built friendly
Installing collected packages: six, executing, asttokens, friendly
Successfully installed asttokens-2.0.5 executing-0.6.0 friendly-0.3.46 six-1.16.0

[hoefling]

@pfmoore ah, so what I have missed is the double negation - thank you for the clarification! Indeed, PIP_NO_BUILD_ISOLATION=0 is the right env var for --no-build-isolation flag. Thank you for your help!