except handler type error should admit the possibility of tuples #5349
Description
$ mypy --version
mypy 0.610
$ cat exception.py
def f() -> None:
excs = [IOError, LookupError]
try:
pass
except excs:
pass
$ mypy exception.py
exception.py:5: error: Exception type must be derived from BaseException
While it's true that this code is incorrect, I probably want to fix it by writing excs = (IOError, LookupError) rather than somehow making my list a subclass of BaseException.