Using the commit hooks on Windows

[Josverl]

I have been struggling to get the commit hooks to work on Windows

• Python 3.11.4
  installed from the Wwindows store
  
• pre-commit 3.3.3
  Installed from PyPi
• Installed the pre-commit hooks with pre-commit install --hook-type pre-commit --hook-type commit-msg as per the docs
• Installed uncrustify 0.72

if I test the pre-commit hooks with: pre-commit run --files .\tools\mpremote\mpremote\main.py

then the output is :

MicroPython codeformat.py for changed files..............................Failed
- hook id: codeformat
- exit code: 1

Executable `python3` not found

ruff.....................................................................Passed

Clearly python3 cannot be found , and that is to be expected as that is not a valid way to start Python on Windows.

Proper ways to specify a manor/minor version are : python -V:3 or 'py -3` or many other ways, however there is no python3 or python3.exe
ref: https://docs.python.org/3.11/using/windows.html

Running codeformat.py directly works fine:

python tools/codeformat.py -v -f .\tools\mpremote\mpremote\main.py 
Identified `C:\develop\MyPython\micropython\tools\mpremote` as project root containing a pyproject.toml.
Sources to be formatted: "mpremote/main.py"
Using configuration from project root.
target_version: ['py34', 'py35', 'py36', 'py37', 'py38', 'py39', 'py310', 'py311']
C:\develop\MyPython\micropython\tools\mpremote\mpremote\main.py already well formatted, good job.

Shebang lines are also supported: https://docs.python.org/3.11/using/windows.html#shebang-lines
However if I change the Shebang to '#!/usr/bin/env python' ( so dropping the 3) suddenly the hooks start to work

So I'm in the dark of how this is supposed to work ( and yes, it works well in *nix , WSL ,containers and in codespaces, so there are work-arounds aplenty)
is this a problem in the hook definition , or is this something that should be raised against the pre-commit repo

So : Has anyone gotten this to work on Windows?

[stinos]

python -V:3

That should also be py -V:3 I guess, because when you write python it's expected that is the actual binary (which has no such argument), not the launcher.

However if I change the Shebang to '#!/usr/bin/env python' ( so dropping the 3) suddenly the hooks start to work

Don't have time to try this now, but: I think that would mean that pre-commit is using the launcher py, so making it use python directly instead might fix things. What's in your .git/hooks/pre-commit ? Maybe that one can be changed, or there's a way to tell pre-commit install what to use.

[Josverl]

did some rip and rebuild to figure this out:

• Uninstalled all python version and launchers
• Found that there was a python3 > py.exe powershell alias defined for powershell. ( get-alias python)
  I must have created this in an earlier attempt to get this to work. Flash is not the only memory that can degrade apparently. (that was also why python appeared to accept the -V:3 , that was actually py.exe'

Then :

• Install python 3.11 from the Windows store

  > python --version  
  Python 3.11.4
  > python3 --version 
   python3 : The term 'python3' is not recognized as the name of a cmdlet, function, script file, or operable program
  

• checked Windows Application Aliases ( in Settings) , and found that the 'App aliases' for python3 and python3.11 were not enabled.
  

• Enabled the alias for python3

  python3 --version
  Python 3.11.4

• created a new venv

• installed pre-commit and the hooks

• found the the pre-commit hook now runs as expected

MicroPython codeformat.py for changed files..............................Passed
- hook id: codeformat
- duration: 1.02s

Identified `C:\develop\MyPython\micropython\tools\mpremote` as project root containing a pyproject.toml.
Using configuration from project root.
target_version: ['py34', 'py35', 'py36', 'py37', 'py38', 'py39', 'py310', 'py311', 'py312']
Found input source: "mpremote/main.py"
C:\develop\MyPython\micropython\tools\mpremote\mpremote\main.py already well formatted, good job.

All done! \u2728 \U0001f370 \u2728
1 file left unchanged.

ruff.....................................................................Passed

success!

Root cause : attempts to create a python3 alias in powershell .

Further testing also shows that the python3 Windows App Alias is indeed required.

[scruss]

... the 'App aliases' for python3 and python3.11 were not enabled.

The Windows convention for naming Python 3 is seemingly at odds with the Linux and Mac standards: the command python shouldn't launch any interpreter on those systems, and python3 is the one to use. If there's still the obsolete Python 2 interpreter on your system, that's the one launched by the python command.

[Josverl]

The convention was created by the folks at python.org. See links above.
The python 3 app aliasses are curtesy of the store app, they are part of the application package.

No python 2 needed, nor installed in the last 3 years.

But hey I always think the dashboard of my neighbor's car looks a bit strange as well 😉

[stinos]

FWIW I tried this in an anaconda environment on windows and that has similar issues. Even though pre-commit knows which python version I'd want it to use (it's full path is in the hooks\pre-commit file after installing), when running it wants a python3 executable which I do not have. I don't immediately see a way to make it use python instead, but a hacky workaround is to symlink python3 to python.

[Josverl]

symlink python3 to python.

I think that is what the windows store aliasses do under the covers

[Josverl]

After re-install python yet again - but now not form the store - i ran into this issue again

Documenting the steps to to create the python3.exe Symlink

Run in a Elevated powershell prompt.

# adjust the path for your version of python
cd $env:userprofile\AppData\Local\Programs\Python\Python311 
new-item python3.exe -itemtype SymbolicLink -Value python.exe