Incorrect return type assumed for "repr()" builtin function with "language_level=3"

[LordAro]

Cython version 0.29.21

def f() -> str:
    return repr('')

with cython -3 -o foo.c foo.py
results in an error:

Error compiling Cython file:
------------------------------------------------------------
...
def f() -> str:
    return repr('')
              ^
------------------------------------------------------------

foo.py:2:15: str objects do not support coercion to unicode, use a unicode string literal instead (u'')

As far as I'm aware, repr() returns a string, so there shouldn't be any issue here? Wrapping it str(repr('')) works fine.

[LordAro]

Doesn't have an issue with it when using -2 either

[scoder]

Thanks for the report. The return type of repr() was declared as str, which is technically correct, but then wasn't adapted to language_level=3, where it should have been unicode.

I've removed the return type declaration so that it now returns object. That's less helpful but prevents failures like in your example.