Bump mypy to 1.11.1 - #12463

There are tons of new errors due to new checks of "untyped code". I will see how easy it would be to fix them.

Well, there are so many errors that I start to think that it might be a regression in mypy: https://github.com/python/typeshed/actions/runs/10187104121/job/28180408403?pr=12463 cc @hauntsaninja

There are also many type: ignore comments that we can get rid of with this release, but they don't show up in CI: see #12178 (comment). Remember that --warn-unused-ignore doesn't work in typeshed directories out of the box.

The changes to the overload-overlap error code are a result of python/mypy#17392. Overall we should be able to get rid of more type: ignore[overload-overlap] comments than we have to add as a result of that change.

The new override errors are a result of python/mypy#17276.

At first glance I think everything is working as expected here; I doubt there's a mypy regression to report

We could do #12178 now if that makes transition easier. I don't think it's critical to do it after the mypy update.

@srittau @AlexWaygood any ideas on why stubtest ignores --mypy-config-file option with [mypy]\ndisable_error_code = overload-overlap inside?

@srittau @AlexWaygood any ideas on why stubtest ignores --mypy-config-file option with [mypy]\ndisable_error_code = overload-overlap inside?

Maybe it's because it doesn't have a file ending? So it doesn't know whether it should use the INI or TOML parser, so it doesn't use either and the file is just silently ignored. Is there any reason not to put a [tool.mypy] section into the pyproject.toml for the part of the configuration that's the same for every mypy/stubtest run and use that instead of a common set of static command line arguments and generating a temporary config file for stubtest? I feel like that would help with setting up contributor's development environments to more closely match what the CI will check. So they don't manually have to match their editor/IDE's configuration, since the pyproject.toml will generally be auto-discovered by tools.

Edit: It also makes it easier to discover what checks are enabled/disabled by default in typeshed.

Is there any reason not to put a [tool.mypy] section into the pyproject.toml for the part of the configuration that's the same for every mypy/stubtest run and use that instead of a common set of static command line arguments and generating a temporary config file for stubtest?

@Daverball we've discussed that idea previously in #2852. I think it would honestly just make our config situation more complicated, because different tests are still going to require slightly different options. It'll be hard to tell which options are provided by the global config and which are overridden in the specific test script, and it could mislead contributors into thinking that running mypy on typeshed is simpler than it is.

Nope, explicit extension didn't work:

Command run was: /opt/hostedtoolcache/Python/3.8.18/x64/bin/python -m mypy.stubtest --check-typeshed --custom-typeshed-dir . --allowlist stdlib/@tests/stubtest_allowlists/common.txt --allowlist stdlib/@tests/stubtest_allowlists/linux.txt --allowlist stdlib/@tests/stubtest_allowlists/py38.txt --allowlist stdlib/@tests/stubtest_allowlists/linux-py38.txt --mypy-config-file /tmp/tmpoc4g5odk.ini --ignore-positional-only

Looks like I will be debugging this manually now :)

This is a mypy bug :)
I will report and fix it today.

If anyone is interested in reviewing my PR it is here: python/mypy#17629

I dropped all config changes, because it is not yet supported by stubtest (until next release).

Ok, the first part is done. Now I will run tests with --warn-unused-ignores and remove unused ignores (there might be many of them).

@srittau @AlexWaygood done! It took me quite some time to finish, but now it is ready! 🎉

Diff from mypy_primer, showing the effect of this PR on open source code:

bokeh (https://github.com/bokeh/bokeh)
- src/bokeh/models/util/structure.py:165: note: ... from here:

cwltool (https://github.com/common-workflow-language/cwltool)
- note: ... from here,
- note: ... from here,
- cwltool/utils.py:52: note: ... from here: