homepage

> self.assertIsInstance(e.pw_gecos, str)
This test is wrong: it's perfectly fine to get None here.
Python must not test the OS itself, but only test our own code: make sure that Python converts properly C types to nice Python types, so a string or None.
I propose to use something like:
def check_type(field):
 self.assertTrue(field is None or isinstance(field, str), repr(field))
...
check_type(e.pw_gecos)