`mypy` pre-commit failure

[jrbourbeau]

When I run pre-commit run mypy --all-files locally on main I get the following failure:

mypy.....................................................................Failed
- hook id: mypy
- exit code: 1

distributed/system_monitor.py:73: error: Statement is unreachable  [unreachable]
Found 1 error in 1 file (checked 279 source files)

mypy.....................................................................Failed
- hook id: mypy
- exit code: 1

distributed/system_monitor.py:73: error: Statement is unreachable  [unreachable]
Found 1 error in 1 file (checked 279 source files)

I suspect that (1) this is related to #7131 (2) this is just an issue with my local environment as our pre-commit CI build is passing on main.

@crusaderky @wence- do either of you have thoughts on how I can resolve this error?

[jrbourbeau]

Running pre-commit clean and then re-installing things seemed to get the job done. Closing for now, but I'd still be curious to know if there's a better way

[wence-]

You can bump the sequence count at the bottom of .pre-commit-config.yaml to ask pre-commit to reinitialize the environment (this is cheaper than pre-commit clean for the case where you have many repos that all use pre-commit). Unfortunately there doesn't seem to be a way to update the environment other than this (I think pre-commit assumes that the hash value of the .pre-commit-config.yaml is a stable key for an environment but without full specification of transitive dependencies with pinning this is not the case).

[jrbourbeau]

You can bump the sequence count at the bottom of .pre-commit-config.yaml to ask pre-commit to reinitialize the environment

Ah I wasn't aware of that, thanks for pointing that out.

I see #7131 did increment that sequence comment. Wouldn't having the latest main locally (i.e. having the updated comment) have fixed this locally then? Or am I missing something?

[crusaderky]

Yes bumping that number should wipe ~/.cache/pre-commit, whether you're running locally or on CI.

[crusaderky]

Correction, it seems that that line is inconsequential. Manually removing ~/.cache/pre-commit fixes the problem for me.
I'm removing the line as it is misleading.

[crusaderky]

Running pre-commit clean and then re-installing things seemed to get the job done. Closing for now, but I'd still be curious to know if there's a better way

The problem is that you can't do that on CI