"Permission Denied" trying to run Python on Windows 10

Seems as though an update on Windows 10 overnight broke Python. Just trying to run python --version returned a "Permission Denied" error. None of the three updates; KB4507453, KB4506991, or KB4509096 look like they'd be the culprit but the timing of the issue is suspicious. Rather than messing with rolling back, I'm hoping there's a simpler fix that I'm missing.

The permissions on python are "-rwxr-xr-x" and I haven't changed anything besides letting the Windows update reboot machine after installing last night's patches.

According to the System Information, I'm running 10.0.18362

Should also note that this is happening whether I (try) to execute Python from git-bash using "run as administrator" or not, and if I try using PowerShell, it just opens the Windows store as if the app isn't installed so I'm thinking it can't see the contents of my /c/Users/david/AppData/Local/Microsoft/WindowsApps/ folder for some reason.

I've also tried to reinstall Python 3.7.4, but that didn't help either. Is there something else I should be looking at?

Answer

November 22, 2020

KyleMit

This is due to the way Windows App Execution Aliases work in Git-Bash.

It is a known issue in MSYS2 failing to access Windows reparse points with IO_REPARSE_TAG_APPEXECLINK

As a workaround, you can alias to a function invocation that uses cmd.exe under the hood.

Add the following to your ~/.bashrc file::

function python { cmd.exe /c "python $1 $2 $3";}

For python, I'd recommend just toggling off app execution aliases as in the accepted answer, but for libraries that are distributed exclusively through the windows store like winget, this is your best option.

Answer

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