Incorrect number of type arguments causes internal error

[bcdarwin]

from typing import TypeVar

T = TypeVar('T')

class C(object):  # forgot to add type params here
    def __init__(self, t : T) -> None:
        self.t   = t

c = C(t = 3)  # type: C[int]  # this will crash

causes:

Traceback (most recent call last):
    ...
    cb = infer_constraints(mapped.args[i], instance.args[i],
IndexError: list index out of range

I guess this generalizes #981 and provides an additional example, here with an (accidentally) non-generic type (though the same happens if too few type arguments are supplied). I'm not sure if it overlaps with #300.

[gvanrossum]

Hm... I'm seeing IndexError too, in a slightly different context (#991). Which version of mypy did you use? (The one from PyPI is way out of date -- #991 is with the current development HEAD.)

[refi64]

I think I found the issue! Hold on...

[bcdarwin]

It's a recent install from master, though I don't know how to (easily) find the commit.

[JukkaL]

I was able to repro this. Thanks for reporting the bug!

[refi64]

@JukkaL I fixed it already!