I used setup.py install today to install matplotlib in a venv. I got some rather hard to tackle tracebacks, as they were filled with exec's (meaning one can not see what the actual code is that fails).

Ultimately this was caused by pyparsing calling .filename and .lineno on a tuple (it obviously expected some kind of different object). But the tuple did contain a filename and a lineno as the first two elements, and some other stuff (the tuple seemed to be coming from the backtrace package). This code was wrapped in something like if PY3: ...

As a random guess I decided to downgrade pyparsing from 2.1.2 to 2.1.1, and this solved the problem. Unfortunately, I am not able to reproduce this anymore, even when upgrading pyparsing to 2.1.2. Still I though a heads-up might be in place, if someone seems AttributeError: 'tuple' object has no attribute 'filename' with a traceback that is more of less useless.