python / python/mypy

False positive `[call-arg]` with `functools.partial` and `concurrent.futures.Executor.submit`

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Description

I get false positive [call-arg] when I apply functools.partial to concurrent.futures.Executor.submit. I see a bunch of opened partial-related issues, but I can't understand if my use case is a duplicate (if it is so—I am sorry for the noise). I've tried to reproduce this without concurrent.futures but got no luck.

To Reproduce

Actual Behavior

Versions 1.10.1 and earlier—no errors (expected behaviour).

Versions 1.11.01.13.0:

main.py:11: error: Missing positional argument "parameter" in call to "submit" of "Executor"  [call-arg]

Versions from 1.14.0 up to the "master branch":

main.py:11: error: Missing positional argument "parameter" in call to "submit" of "Executor"  [call-arg]
main.py:11: error: Too few arguments for "submit" of "Executor"  [call-arg]

Your Environment

I've played in playground with its default settings (i.e. no options were checked) and Python versions 3.12 and 3.13.

Contributor guide

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the diagnostic with the linked gist or mypy playground across the listed versions, then inspect how functools.partial and concurrent.futures.Executor.submit are handled. Done means the reproduced valid call no longer emits the [call-arg] errors while existing argument checking remains intact.

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Assessment

Tech stack
python
Domain
compilers, devtools
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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