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te 4.7.0 breaks Mypy daemon on Python 3.7 (TypeError: metaclass conflict) #265
Description
Using typing-extensions 4.7.0 on Python 3.7 breaks the Mypy daemon:
$ dmypy run src/
Traceback (most recent call last):
File "mypy/dmypy/client.py", line 274, in main
File "mypy/dmypy/client.py", line 394, in do_run
File "mypy/dmypy/client.py", line 350, in start_server
File "mypy/dmypy_server.py", line 35, in <module>
from mypy.suggestions import SuggestionEngine, SuggestionFailure
File "mypy/suggestions.py", line 86, in <module>
class PyAnnotateSignature(TypedDict):
TypeError: metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases
Pinning typing-extensions 4.6.3 fixes this error. It seems like a break in backwards compatibility in typing-extensions.
Activity
JelleZijlstra commentedon Jul 2, 2023
This was fixed in mypy recently (python/mypy#15543) but not released. Given that 3.7 has reached its end of life, we're not planning to fix this in typing-extensions.
Set upper constraint for typing-extensions due to python/typing_exten…
NiklasRosenstein commentedon Jul 2, 2023
Thanks for the fast response.
Could you tell me why
typing-extension 4.7.0is stilled tagged withrequires-python = ">=3.7"then? Would it make sense to yank4.7.0and4.7.1and update that to>=3.8?Add `Property.required()` and `Property.help`, remove `Property.confi…
JelleZijlstra commentedon Jul 2, 2023
typing-extensions 4.7 generally works fine with Python 3.7. It's broken only when using dmypy (not mypy itself, which apparently doesn't use any TypedDict), or potentially with other mypyc-compiled applications that use TypedDict. A relatively obscure case in a single third-party tool on a version that has reached end of life isn't enough to justify yanking the release.
Set an upper bound for typing-extensions due to python/typing_extensi…
Add `Property.required()` and `Property.help`, remove `Property.confi…