mypy RecursionError analyzing pint.facets.plain.quantity.PlainQuantity

Crash Report

mypy crashes with RecursionError while analyzing pint (since pint==0.26.1). Reproduced with compiled and non-compiled mypy.

Traceback

... skipping approx 50000 lines ...
  File "/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/mypy/type_visitor.py", line 560, in visit_instance
    return self.query_types(t.args)
           ~~~~~~~~~~~~~~~~^^^^^^^^
  File "/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/mypy/type_visitor.py", line 628, in query_types
    return any(t.accept(self) for t in types)
  File "/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/mypy/type_visitor.py", line 628, in <genexpr>
    return any(t.accept(self) for t in types)
               ~~~~~~~~^^^^^^
  File "/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/mypy/types.py", line 1684, in accept
    return visitor.visit_instance(self)
           ~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/mypy/type_visitor.py", line 560, in visit_instance
    return self.query_types(t.args)
           ~~~~~~~~~~~~~~~~^^^^^^^^
  File "/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/mypy/type_visitor.py", line 628, in query_types
    return any(t.accept(self) for t in types)
  File "/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/mypy/type_visitor.py", line 628, in <genexpr>
    return any(t.accept(self) for t in types)
               ~~~~~~~~^^^^^^
  File "/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/mypy/types.py", line 1684, in accept
    return visitor.visit_instance(self)
           ~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/mypy/type_visitor.py", line 560, in visit_instance
    return self.query_types(t.args)
           ~~~~~~~~~~~~~~~~^^^^^^^^
  File "/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/mypy/type_visitor.py", line 628, in query_types
    return any(t.accept(self) for t in types)
  File "/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/mypy/type_visitor.py", line 628, in <genexpr>
    return any(t.accept(self) for t in types)
               ~~~~~~~~^^^^^^
  File "/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/mypy/types.py", line 1684, in accept
    return visitor.visit_instance(self)
           ~~~~~~~~~~~~~~~~~~~~~~^^^^^^
RecursionError: maximum recursion depth exceeded
/home/quentin/dev/QSA/pint_0.x/.venv/lib/python3.13/site-packages/pint/facets/numpy/quantity.py:63: note: use --pdb to drop into pdb
RecursionError: maximum recursion depth exceeded

To Reproduce

I narrowed down the issue to this single import of pint.facets.plain.quantity.PlainQuantity.
Run mypy on a file with this content:

from pint.facets.plain.quantity import PlainQuantity

Your Environment

Issue appears since version 0.26 of pint when they introduced massive type annotations for PlainQuantity. See https://github.com/hgrecco/pint/pull/2302 and https://github.com/hgrecco/pint/pull/2303

• Mypy version used: 2.3.1 and 1.9.1
• Mypy command-line flags: none
• Mypy configuration options from mypy.ini (and other config files): none
• Python version used: 3.13.12
• Operating system and version: Fedora 43 in WSL2

Inizia riproducendo il crash con mypy in un file che importa pint.facets.plain.quantity.PlainQuantity. Segui la ricorsione attraverso i percorsi menzionati type_visitor.py e types.py, quindi verifica che l’analisi dello stesso import venga completata senza RecursionError.