__getnewargs__ for a subclass incompatible with return type of supertype

Here is an example commit with the issue: https://github.com/eli-schwartz/meson/commit/4d204bb81869422a102264611d9aea314a1ac2ca

mypy.ini: https://github.com/mesonbuild/meson/blob/27626124d0bdd89f5f276f70a73b4713aa3aac3d/.mypy.ini

$ mypy --version
mypy 0.961 (compiled: yes)

$ mypy mesonbuild/interpreter/primitives/string.py
mesonbuild/interpreter/primitives/string.py:211:5: error: Return type "Tuple[str, str]" of "__getnewargs__" incompatible with return type "Tuple[str]" in supertype "str"

I subclassed str and treat it specially with its own incompatible __new__() to enforce a specific creation pattern. After discovering I need to pickle it as well, I added a __getnewargs__() which is also incompatible. mypy is happy with my incompatible new, but not with the getnewargs that needs to match the argument contract of new.

Riproduci il report con mypy 0.961 usando mesonbuild/interpreter/primitives/string.py e la configurazione .mypy.ini collegata. Esamina come vengono verificate rispetto a str le firme di new e getnewargs della sottoclasse, quindi verifica che il caso pickle previsto sia gestito senza la diagnostica di ritorno incompatibile segnalata.