Usage error when using --find-occurrences

[JeroenSchmidt]

Hi All,
I am trying to use --find-occurrences but it looks like it might be broken.
I could also be reading --help wrong; in that case it would help if there was clear documentation on how to use it - related #2042

Commands tried:

python -m mypy <path_to_project>/some_module.py --find-occurrences Example.ClassName
python -m mypy <path_to_project>/some_module.py --find-occurrences "(Example.ClassName)"
python -m mypy <path_to_project>/some_module.py --find-occurrences "(Example,ClassName)"
python -m mypy <path_to_project>/some_module.py --find-occurrences

Output

Traceback (most recent call last):
  File "/Users/user/miniconda3/envs/bkng-data-lineage2/lib/python3.10/runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/Users/user/miniconda3/envs/bkng-data-lineage2/lib/python3.10/runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "/Users/user/miniconda3/envs/bkng-data-lineage2/lib/python3.10/site-packages/mypy/__main__.py", line 37, in <module>
    console_entry()
  File "/Users/user/miniconda3/envs/bkng-data-lineage2/lib/python3.10/site-packages/mypy/__main__.py", line 15, in console_entry
    main()
  File "mypy/main.py", line 66, in main
  File "mypy/main.py", line 1335, in process_options
TypeError: tuple[str, str] or None object expected; got list

Your Environment

• Mypy version used: mypy==1.4.1, mypy-extensions==1.0.0, pylsp-mypy==0.6.7
• Mypy configuration options: None
• Python version used: 3.10

[hauntsaninja]

Oh interesting, I didn't know this was an option. Looks like it's documented as experimental. Anyway easy enough to fix...

[hauntsaninja]

As a workaround, you could probably install mypy without mypyc, e.g. via pip install --no-binary mypy (note: this version of mypy will be significantly slower than the usual one)

[JeroenSchmidt]

Thanks @hauntsaninja I'll try the work around.
To anyone else reading this you need to run pip install --no-binary mypy mypy - the command above doesn't work

[JeroenSchmidt]

@hauntsaninja it might be out of scope for this bug report but I noticed that --find-occurrences silently does nothing if a .mypy_cache exists. The solution is to remove it before every time running --find-occurrences.

[hauntsaninja]

A slightly more ergonomic workaround would be to pass --no-incremental to mypy. I'm not planning on fixing that, but you might be able to make a PR to fix? Likely just setting options.incremental = False in the right place would fix.

[JeroenSchmidt]

@hauntsaninja will do. Thank you for the help.