reveal_type hides errors when --allow-redefinition is used

[KotlinIsland]

a = 2
reveal_type(a)  # Revealed type is 'builtins.int'
a = "asdf"

note: Revealed type is 'builtins.int'

[hauntsaninja]

I can't repro

[KotlinIsland]

@hauntsaninja I can reproduce:

[hauntsaninja]

Maybe try sharing a repro from https://mypy-play.net?
Obviously as the filer of this issue you can repro; repeating that information doesn't help. On the other hand, filling out the information the issue template asks for, e.g. like your mypy version, does.

[hauntsaninja]

E.g. https://mypy-play.net/?mypy=latest&python=3.9&flags=strict&gist=07840bf89fe7ef07e4e3521d1a3708a9 shows that I can't reproduce the lack of error based on what you've posted so far

[KotlinIsland]

Oh sorry, my bad. I forgot I had a mypy.ini, it's --allow-redefinition

[KotlinIsland]

mypy playground doesn't have an option for allow-redefinition?

[hauntsaninja]

If you have --allow-redefinition then your code isn't incorrect. The behaviour changes due to reveal_type (but substitute literally any use of a) because of #6963

[hauntsaninja]

Yusuke would probably happily accept a PR adding the option to mypy playground at https://github.com/ymyzk/mypy-playground/pulls :-)