Message 101876 - Python tracker
Confirmed.
There's something wrong around the doctest._SpoofOut class.
This script triggers the same bug (both 3.x and 3.1).
Output:
$ ./python issue8256_case.py
prompt:
Traceback (most recent call last):
File "issue8256_case.py", line 13, in <module>
foo()
File "issue8256_case.py", line 7, in foo
print()
TypeError: bad argument type for built-in operation