Unable to use TypeAlias about typing_extensions

[hauntsaninja]

Hmm, not sure the actual version of typing_extensions should matter (at least at type check time, which OP's error definitely is); mypy should just be looking at the typeshed stubs.

(In fact, mypy thinks typing_extensions is part of the standard library, so you can actually type check without having it installed, like in the days before modular typeshed)

If OP could provide a script that reproduces the error, ideally from a fresh virtual environment, that would be very helpful!

[srittau]

Maybe @nipunn1313 has some insight what could be wrong here.

[hauntsaninja]

What mypy version are you using? Try 0.930

[nipunn1313]

It requires mypy 0.930

if you can’t resolve:

What version of mypy, mypy_protobuf, and python are you using?

[siddharthrajaraja]

I used python 3.8.x , mypy 0.930 and my_protobuf 3.1.0 @nipunn1313

[siddharthrajaraja]

@nipunn1313 , it will be good if you help me out with exact versions needed to resolve this issue

[nipunn1313]

Hmm.

Ok here's a hypothesis.
What version of typing_extensions do you have?

 pip3 show typing_extensions

It looks like it was added with python/typing@6d287f0 in 3.7.4.2 (which released July 2020). Is it possible you have a version older than that installed?

If this is the case leading to the issue, I think the more permanent solution is to add it to the setup requirements for mypy-protobuf (https://github.com/dropbox/mypy-protobuf/blob/main/setup.cfg#L19), and the documentation.

Sorry for the trouble - hoping you can help validate if this hypothesis and see if it helps with the issue.

[siddharthrajaraja]

We can mark this closed as I changed the mypy version to latest and it worked for me. Thanks everyone.