Created attachment 871928 [details] Minimal reproducer Description of problem: Accidentaly I called xml_f() method on Comps() python object with wrong argument. Instead of immediate TypeError exception I receive TypeError when I try to use iteration on different object. Version-Release number of selected component (if applicable): libcomps-0.1.6-3.fc21.x86_64 python-libcomps-0.1.6-3.fc21.x86_64 python-2.7.5-11.fc20.x86_64 How reproducible: Always Steps to Reproduce: 1. Run attached p.py: python p.py Actual results: Traceback (most recent call last): File "p.py", line 7, in <module> print [b for b in x] TypeError: 'foo' is an invalid keyword argument for this function Expected results: TypeError on line with xml_f() call. Additional info: