usage of `ellipsis` type should be an error

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foo: ellipsis = ...

https://mypy-play.net/?mypy=master&python=3.10&gist=c2d3912a93b253bbf3f0589148d945bf

this fails at runtime because ellipsis doesn't exist

[erictraut]

This appears to be a bug in typeshed's builtins.pyi file, which declares this symbol in the builtins namespace. Perhaps it should be moved to _typeshed.pyi or renamed _ellipsis to indicate that it's private?

[emmatyping]

Yeah, I think this should probably be reported against typeshed, thanks for debugging that Eric!

[DetachHead]

python/typeshed#3556

[DetachHead]

i think this should be reopened as it looks like there's a change required on the mypy side in order to fix it. see python/typeshed#3556 (comment)

also see the mypy crashes on python/typeshed#6311

[JelleZijlstra]

Yes, this is one of the instances where typeshed can't change until mypy changes. #3171 discusses the analogous issue with builtins.function.