Incompatible bounds on type variable when using unbound method with map()

[besfahbod]

Given:

list(map(str.strip, fields))

We get this error:

E         Cannot call overloaded function (code: incompatible_call)
E             In overload (func: (~_T1, /) -> ~_S, iter1: collections.abc.Iterable[~_T1], /) -> map[~_S]
E               Cannot resolve type variables
E                     Incompatible bounds on type variable
E                       str is not a literal
E                         LiteralString >= ~_T1
E                         str <= ~_T1
E
E
E         In /home/[...] at line 77
E           77:             list(map(str.strip, fields))
E                                ^