`_distutils_hack` fails if called anything but `get-pip.py`

Description

Pip fails to install:

which python
# /usr/local/opt/python/libexec/bin/python
/usr/local/opt/python/libexec/bin/python --version
# Python 3.9.10
down https://bootstrap.pypa.io/get-pip.py --destination=/var/folders/wm/8g56ry4s47z_hbt0tgv0m5gr0000gn/T/tmp.vv6opZCN
# down is an internal command
python /var/folders/wm/8g56ry4s47z_hbt0tgv0m5gr0000gn/T/tmp.vv6opZCN --user
# fails and outputs the next code block

/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/__init__.py:17: UserWarning: Distutils was imported before Setuptools, but importing Setuptools also replaces the `distutils` module in `sys.modules`. This may lead to undesirable behaviors or errors. To avoid these issues, avoid using distutils directly, ensure that setuptools is in/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/__init__.py:30File "/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/overrideFile "/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/__init__File "/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/__init__/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/__init__.py:17: UserWarning: Distutils was imported before Setuptools, but importing Setuptools also replaces the `distutils` module in `sys.modules`. This may lead to undesirable behaviors or errors. To avoid these issues, avoid using distutils directly, ensure that setuptools is installed in the traditional way (e.g. not an editable install), and/or make sure that setuptools is always imported before distutils.
  warnings.warn(
/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/__init__.py:30: UserWarning: Setuptools is replacing distutils.
  warnings.warn("Setuptools is replacing distutils.")
Traceback (most recent call last):
  File "/var/folders/wm/8g56ry4s47z_hbt0tgv0m5gr0000gn/T/tmp.vv6opZCN", line 27081, in <module>
    main()
  File "/var/folders/wm/8g56ry4s47z_hbt0tgv0m5gr0000gn/T/tmp.vv6opZCN", line 139, in main
    bootstrap(tmpdir=tmpdir)
  File "/var/folders/wm/8g56ry4s47z_hbt0tgv0m5gr0000gn/T/tmp.vv6opZCN", line 120, in bootstrap
    args = determine_pip_install_arguments()
  File "/var/folders/wm/8g56ry4s47z_hbt0tgv0m5gr0000gn/T/tmp.vv6opZCN", line 65, in determine_pip_install_arguments
    import setuptools  # noqa
  File "/usr/local/lib/python3.9/site-packages/setuptools/__init__.py", line 8, in <module>
    import _distutils_hack.override  # noqa: F401
  File "/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/override.py", line 1, in <module>
    __import__('_distutils_hack').do_override()
  File "/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/__init__.py", line 71, in do_override
    ensure_local_distutils()
  File "/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/__init__.py", line 59, in ensure_local_distutils
    assert '_distutils' in core.__file__, core.__file__
AssertionError: /usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/core.py

Expected behavior

it to work fine

pip version

latest

Python version

3.9.10

OS

21.2.0 Darwin Kernel Version 21.2.0: Sun Nov 28 20:28:54 PST 2021; root:xnu-8019.61.5~1/RELEASE_X86_64 x86_64

How to Reproduce

this works fine:

brew install python
wget https://bootstrap.pypa.io/get-pip.py
chmod +x ./get-pip.py
python ./get-pip.py --user

this fails, which is common when say saving the installer to a randomly generated temp file:

brew install python
wget https://bootstrap.pypa.io/get-pip.py
mv ./get-pip.py ./any-other-filename.py
chmod +x ./any-other-filename.py
python ./any-other-filename.py --user

Output

Warning: python@3.9 3.9.10 is already installed and up-to-date.
To reinstall 3.9.10, run:
  brew reinstall python@3.9
--2022-01-19 23:48:26--  https://bootstrap.pypa.io/get-pip.py
Resolving bootstrap.pypa.io (bootstrap.pypa.io)... 151.101.52.175, 2a04:4e42:d::175
Connecting to bootstrap.pypa.io (bootstrap.pypa.io)|151.101.52.175|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 2159352 (2.1M) [text/x-python]
Saving to: ‘get-pip.py’

get-pip.py                        100%[============================================================>]   2.06M  1.65MB/s    in 1.2s    

2022-01-19 23:48:28 (1.65 MB/s) - ‘get-pip.py’ saved [2159352/2159352]

/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/__init__.py:17: UserWarning: Distutils was imported before Setuptools, but importing Setuptools also replaces the `distutils` module in `sys.modules`. This may lead to undesirable behaviors or errors. To avoid these issues, avoid using distutils directly, ensure that setuptools is installed in the traditional way (e.g. not an editable install), and/or make sure that setuptools is always imported before distutils.
  warnings.warn(
/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/__init__.py:30: UserWarning: Setuptools is replacing distutils.
  warnings.warn("Setuptools is replacing distutils.")
Traceback (most recent call last):
  File "/Users/balupton/./any-other-filename.py", line 27081, in <module>
    main()
  File "/Users/balupton/./any-other-filename.py", line 139, in main
    bootstrap(tmpdir=tmpdir)
  File "/Users/balupton/./any-other-filename.py", line 120, in bootstrap
    args = determine_pip_install_arguments()
  File "/Users/balupton/./any-other-filename.py", line 65, in determine_pip_install_arguments
    import setuptools  # noqa
  File "/usr/local/lib/python3.9/site-packages/setuptools/__init__.py", line 8, in <module>
    import _distutils_hack.override  # noqa: F401
  File "/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/override.py", line 1, in <module>
    __import__('_distutils_hack').do_override()
  File "/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/__init__.py", line 71, in do_override
    ensure_local_distutils()
  File "/usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/_distutils_hack/__init__.py", line 59, in ensure_local_distutils
    assert '_distutils' in core.__file__, core.__file__
AssertionError: /usr/local/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/core.py

Code of Conduct

• I agree to follow the PSF Code of Conduct.

[jaraco]

I’ve moved your comment to a new issue because it’s a different case.

[jaraco]

I see now that in https://github.com/pypa/get-pip/pull/140, the get-pip script was updated not to import setuptools, and that script was probably updated in get-pip.py in late January, so I suspect the root cause of this issue has been addressed.

If any one else encounters this issue and can reproduce it (preferably in a Docker image) using the latest get-pip, please let us know.