Document or explain "<nothing>"

[ddfisher]

Users can now get <uninhabited> in error messages when there are no constraints on a type variable. This should either be documented somewhere, or we should use a more self-explanatory string to display the type.

[ethanhs]

I would say a better more explanatory error is a better option. I didn't know what it meant till reading more about it, and I expect many others would be similarly confused.

[ddfisher]

Agreed. Though actually the better option still might be to not infer UninhabitedType when there are no constraints on a type variable. (See #3032.)

[ilevkivskyi]

I just renamed the issue since UninhabitedType() is currently formatted as <nothing>.

[GabrielMajeri]

I'm trying to determine where would be the proper place to document this type.
Would the Kind of types page be the correct location for it?

[JukkaL]

Would the Kind of types page be the correct location for it?

These are related to type variables, so somewhere here would be a better location:

https://github.com/python/mypy/blob/master/docs/source/generics.rst

[patrick-nicodemus]

Has there been any progress on this in the past five years?
I have Revealed type is "<nothing>" as an error message and I am not sure how to interpret it.