• cattrs version: 22.2.0
• Python version: 3.8

Description

def my_test():
    @frozen
    class A(Generic[T]):
        a: int
        b: T

    @frozen
    class B:
        pass
    
    cattrs.structure({"a": 1, "b": []}, A[Sequence[B]])
=> Syntax error 

generated function name is: structure_A_typing_Sequence___main___my_test_<locals>_B_
name = re.sub(r"[\[\.\] ,]", "_", name) probably needs to have <> added to make it work :)