Okay, this doesn't strictly block the release, but we should really fit this in.

Here's is the failure case, as it happens on the current release: https://github.com/pradyunsg/testing-grounds/runs/3840831149

> pip install --upgrade pip --force-reinstall
Collecting pip
  Downloading pip-21.2.4-py3-none-any.whl (1.6 MB)
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 21.2.4
    Uninstalling pip-21.2.4:
      Successfully uninstalled pip-21.2.4
ERROR: Could not install packages due to an OSError: [WinError 5] Access is denied: 'C:\\hostedtoolcache\\windows\\Python\\3.9.7\\x64\\~cripts\\pip.exe'
Consider using the `--user` option or check the permissions.

If someone with a Windows machine can confirm that this branch correctly rejects pip install pip --force-reinstall; that'd be great! (you'll need to install this branch in a virtualenv, and then run that command)

If someone with a Windows machine can confirm

Will do, but sorry - what's the correct incantation to install this branch?

python -m pip install https://github.com/pradyunsg/pip/archive/refs/heads/fix-protect-pip-on-windows.zip

I will also try it, I have a Windows 10 machine ;)

Womp womp. The checks we have already seem to not work, because... at least on GitHub actions... pip install pip<=21.2.4 has the following as sys.argv[0].

C:\hostedtoolcache\windows\Python\3.9.7\x64\Scripts\pip

And we're checking for endswith pip.exe. :(

I installed pip on a fresh virtualenv and installed your pip branch. Then I tried these commands. This is my output:

• pip install --upgrade pip --force-reinstall:

(my_venv) C:\Users\Diego Ramirez>pip install pip --force-reinstall
Collecting pip
  Using cached pip-21.2.4-py3-none-any.whl (1.6 MB)
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 21.3.dev0
    Uninstalling pip-21.3.dev0:
      Successfully uninstalled pip-21.3.dev0
ERROR: Could not install packages due to an OSError: [WinError 5] Acceso denegado: 'C:\\Users\\Diego Ramirez\\AppData\\Local\\Temp\\pip-uninstall-m1tyyq18\\pip.exe'
Check the permissions.

Maybe I missed something?

Womp womp. The checks we have already seem to not work, because... at least on GitHub actions... pip install pip<=21.2.4 has the following as sys.argv[0].

C:\hostedtoolcache\windows\Python\3.9.7\x64\Scripts\pip

Yup, I can also confirm that :(

I get the same result as @DiddiLeija. Looks like satisfied_by is None in my case...

Womp womp.

The answer seems to be that it's no longer pip.exe as sys.argv[0] but rather pip, which... is falling through the check for "is this running pip directly".

The answer seems to be that it's no longer pip.exe as sys.argv[0] but rather pip, which... is falling through the check for "is this running pip directly".

Well, let's just check for pip then. python -m pip gives us __main__.py as basename(sys.argv[0]).

Mypy isn't happy now 😅.

Before you merge this, I want to check the behavior once again 😉.

Oh yea, totally cool with that!

There's also an automated test, FWIW, so if that fails, we know that this won't work. :)

Ok, I tried pip install pip --force-reinstall, and failed with this message:

(test-win-pip) C:\Users\Diego Ramirez>pip install pip --force-reinstall
Collecting pip
  Using cached pip-22.0.3-py3-none-any.whl (2.1 MB)
ERROR: To modify pip, please run the following command:
C:\Users\Diego Ramirez\test-win-pip\Scripts\python.exe -m pip install pip --force-reinstall

I think that is what we wanted to do?

Also, I tried python -m pip install pip --force-reinstall. It works as expected:

(test-win-pip) C:\Users\Diego Ramirez>python -m pip install pip --force-reinstall
Collecting pip
  Using cached pip-22.0.3-py3-none-any.whl (2.1 MB)
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 22.1.dev0
    Uninstalling pip-22.1.dev0:
      Successfully uninstalled pip-22.1.dev0
Successfully installed pip-22.0.3

Awesome!

And, now it's #10922 that's necessary for fixing the CI. :)

Merging this on the basis of a bunch of manual tests by myself and @DiddiLeija! If there's any concerns, please feel free to @ mention me here. :)