Run mypy on the CI Python version matrix - #22
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Remove the python_version pin from the mypy configuration and move the type-check step from the lint job into the test matrix. Pinning mypy to 3.11 semantics while running under a newer interpreter made mypy analyse installed third-party packages built for that newer interpreter with the older syntax rules; numpy_typing_compat legitimately uses 3.12+ syntax in such environments, so mypy failed before reaching the package code. With the pin removed, mypy defaults to the interpreter it runs under, so each matrix environment (3.11 to 3.14) type-checks its own semantics against its own installed stubs.
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Summary
mypy lattice_mccurrently fails in any environment newer than Python 3.11 with an error inside the third-partynumpy_typing_compatstubs ("Type statement is only supported in Python 3.12 and greater"). The cause is thepython_version = "3.11"pin in[tool.mypy]: mypy applied 3.11 syntax rules to packages installed for a newer interpreter, and those packages legitimately use 3.12+ syntax on newer Pythons. The CI lint job (Python 3.13) hits exactly this mismatch.Changes
python_versionpin from[tool.mypy]inpyproject.toml, so mypy defaults to the interpreter it runs under and always checks semantics consistent with the installed environment.lintjob into thetestmatrix job, so mypy runs under each supported version (3.11-3.14) with the correspondingly installed dependencies. This is what genuinely verifies 3.11 semantics, rather than emulating them from a newer environment. Thelintjob retains ruff.Verified locally (Python 3.12):
mypy lattice_mcpasses with the pin removed, and the full test suite passes.