runtests.py lint fails in shellcheck, at least on windows

[wyattscarpenter]

> uv run runtests.py lint
run lint: ['pre-commit', 'run', '--all-files']
trim trailing whitespace.................................................Passed
fix end of files.........................................................Passed
black....................................................................Passed
ruff.....................................................................Passed
Validate GitHub Workflows................................................Passed
Validate GitHub Actions..................................................Passed
Validate ReadTheDocs Config..............................................Passed
codespell................................................................Passed
Lint GitHub Actions workflow files.......................................Failed
- hook id: actionlint
- exit code: 3

fatal error while checking .github/workflows/build_wheels.yml: `C:\Users\wyatt\.cache\pre-commit\repovf_fh8ur\golangenv-system\bin\shellcheck.exe --norc -f json -x --shell bash -e SC1091,SC2194,SC2050,SC2154,SC2157,SC2043 -` did not run successfully while checking script at line:25,col:9: C:\Users\wyatt\.cache\pre-commit\repovf_fh8ur\golangenv-system\bin\shellcheck.exe exited with status 1 but stdout was empty. stderr: "2025/09/30 16:02:59 environ invalid: empty key\n"
fatal error while checking .github/workflows/test_stubgenc.yml: `C:\Users\wyatt\.cache\pre-commit\repovf_fh8ur\golangenv-system\bin\shellcheck.exe --norc -f json -x --shell bash -e SC1091,SC2194,SC2050,SC2154,SC2157,SC2043 -` did not run successfully while checking script at line:41,col:7: C:\Users\wyatt\.cache\pre-commit\repovf_fh8ur\golangenv-system\bin\shellcheck.exe exited with status 1 but stdout was empty. stderr: "2025/09/30 16:03:00 environ invalid: empty key\n"

zizmor...................................................................Passed
Bad PR link..............................................................Passed
Check hooks apply to the repository......................................Passed
Check for useless excludes...............................................Passed

FAILED: lint

[wyattscarpenter]

Hmm, now I'm getting

fatal error while checking .github/workflows/docs.yml: `C:\Users\wyatt\.cache\pre-commit\repovf_fh8ur\golangenv-system\bin\shellcheck.exe --norc -f json -x --shell bash -e SC1091,SC2194,SC2050,SC2154,SC2157,SC2043 -` did not run successfully while checking script at line:47,col:9: C:\Users\wyatt\.cache\pre-commit\repovf_fh8ur\golangenv-system\bin\shellcheck.exe exited with status 1 but stdout was empty. stderr: "2025/09/30 16:26:54 environ invalid: empty key\n"
fatal error while checking .github/workflows/test_stubgenc.yml: `C:\Users\wyatt\.cache\pre-commit\repovf_fh8ur\golangenv-system\bin\shellcheck.exe --norc -f json -x --shell bash -e SC1091,SC2194,SC2050,SC2154,SC2157,SC2043 -` did not run successfully while checking script at line:41,col:7: C:\Users\wyatt\.cache\pre-commit\repovf_fh8ur\golangenv-system\bin\shellcheck.exe exited with status 1 but stdout was empty. stderr: "2025/09/30 16:26:57 environ invalid: empty key\n"

[wyattscarpenter]

Actually it does this when I directly run it, with no files :/

I can't even get to the --help text for this shellcheck.exe

[wyattscarpenter]

Sadly, incrementing the version in

mypy/.pre-commit-config.yaml

Line 44 in 6feecce

- "github.com/wasilibs/go-shellcheck/cmd/shellcheck@v0.10.0"

to the latest v0.11.0 (https://github.com/wasilibs/go-shellcheck/releases/tag/v0.11.0) does not fix this problem. Nor did making it @latest.

[sterliakov]

Probably Windows is the clue here. I'm usually just running git commit (or pre-commit run -a -v if I only want to format but not ready to commit), but runtests.py works as well on my Lubuntu box:

$ uv run runtests.py lint
Using CPython 3.10.13
Removed virtual environment at: .venv
Creating virtual environment at: .venv
      Built mypy @ file:///home/stas/Documents/Work/mypy
Installed 5 packages in 5ms
run lint: ['pre-commit', 'run', '--all-files']
trim trailing whitespace.................................................Passed
fix end of files.........................................................Passed
black....................................................................Passed
ruff.....................................................................Passed
Validate GitHub Workflows................................................Passed
Validate GitHub Actions..................................................Passed
Validate ReadTheDocs Config..............................................Passed
codespell................................................................Passed
Lint GitHub Actions workflow files.......................................Passed
zizmor...................................................................Passed
Bad PR link..............................................................Passed
Check hooks apply to the repository......................................Passed
Check for useless excludes...............................................Passed

Furthermore, somehow your problem seems to be unique - I can't find any references to it neither in the shellcheck repo nor in the wasilibs mirror. I can't even locate any mention of "environ invalid: empty key" anywhere, googling that quoted produces no results. You must be really unlucky...

Do you have Go installed on your machine? If yes - what version? I can hardly help with Win debugging, but let's try - pre-commit docs mention that it uses system golang installation if it exists. So if you have a system installation, try to upgrade or remove it, if you don't - maybe try to install?

And to be clear, uv run lint is equivalent to pre-commit run -a, so you can simply not use it if the problem doesn't go away; git commit will invoke pre-commit, and this hook will be skipped unless you edit the workflows in .github. If your git commit does not invoke linters, you forgot to pre-commit install them

[wyattscarpenter]

I'm always cognizant of the possibility that my computer in particular might just be cursed; it often is.

I just fresh-installed python 3.9 and newly cloned github.com/python/mypy to see if that would help; alas, same error.

That's a good idea, about go! I seem to have go version go1.24.3 windows/amd64 installed. I'm now uninstalling it...

[wyattscarpenter]

Sadly, this seems to have made no difference.

>uv run runtests.py lint
run lint: ['pre-commit', 'run', '--all-files']
[INFO] Initializing environment for https://github.com/pre-commit/pre-commit-hooks.
[INFO] Initializing environment for https://github.com/psf/black-pre-commit-mirror.
[INFO] Initializing environment for https://github.com/astral-sh/ruff-pre-commit.
[INFO] Initializing environment for https://github.com/python-jsonschema/check-jsonschema.
[INFO] Initializing environment for https://github.com/codespell-project/codespell.
[INFO] Initializing environment for https://github.com/rhysd/actionlint.
[INFO] Initializing environment for https://github.com/rhysd/actionlint:github.com/wasilibs/go-shellcheck/cmd/shellcheck@v0.10.0.
[INFO] Initializing environment for https://github.com/woodruffw/zizmor-pre-commit.
[INFO] Installing environment for https://github.com/pre-commit/pre-commit-hooks.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/psf/black-pre-commit-mirror.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/astral-sh/ruff-pre-commit.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/python-jsonschema/check-jsonschema.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/codespell-project/codespell.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/rhysd/actionlint.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/woodruffw/zizmor-pre-commit.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
trim trailing whitespace.................................................Passed
fix end of files.........................................................Passed
black....................................................................Passed
ruff.....................................................................Passed
Validate GitHub Workflows................................................Passed
Validate GitHub Actions..................................................Passed
Validate ReadTheDocs Config..............................................Passed
codespell................................................................Passed
Lint GitHub Actions workflow files.......................................Failed
- hook id: actionlint
- exit code: 3

fatal error while checking .github/workflows/build_wheels.yml: `C:\Users\wyatt\.cache\pre-commit\repodf95ll9p\golangenv-default\bin\shellcheck.exe --norc -f json -x --shell bash -e SC1091,SC2194,SC2050,SC2154,SC2157,SC2043 -` did not run successfully while checking script at line:25,col:9: C:\Users\wyatt\.cache\pre-commit\repodf95ll9p\golangenv-default\bin\shellcheck.exe exited with status 1 but stdout was empty. stderr: "2025/09/30 21:16:32 environ invalid: empty key\n"
fatal error while checking .github/workflows/mypy_primer_comment.yml: `C:\Users\wyatt\.cache\pre-commit\repodf95ll9p\golangenv-default\bin\shellcheck.exe --norc -f json -x --shell bash -e SC1091,SC2194,SC2050,SC2154,SC2157,SC2043 -` did not run successfully while checking script at line:42,col:9: C:\Users\wyatt\.cache\pre-commit\repodf95ll9p\golangenv-default\bin\shellcheck.exe exited with status 1 but stdout was empty. stderr: "2025/09/30 21:16:33 environ invalid: empty key\n"

zizmor...................................................................Passed
Bad PR link..............................................................Passed
Check hooks apply to the repository......................................Passed
Check for useless excludes...............................................Passed

FAILED: lint

[wyattscarpenter]

This wouldn't be so bad, except it also causes runtests.py to early fail, making it harder to run the whole test suite. There is always tox, however. (edit: tox seems to crash my computer lol)

[wyattscarpenter]

Lints fine in WSL2 (Ubuntu-24.04), though.

I have another windows machine I can also try this on in a couple of days.

[sterliakov]

tox seems to crash my computer lol

Okay, and this sounds like a good reason to assume that smth is wrong with your specific setup... I heard people "just" reinstall Windows when it becomes completely unbearable, have you considered such an option?

[wyattscarpenter]

Ah, I forgot to update that sentence once I narrowed down the problem. It's simply that if I run too many tests at the same time my computer gives up and shuts down. Running tox normally (and not twice in two different configurations in two different repositories at the same time) actually works fine for me. Red herring. It still has the lint failure on Windows, of course, but it doesn't halt to early-out.

[wyattscarpenter]

I was able to replicate on my other machine, which has Windows 11 with python 3.13.