Is there any way to know what line number an error originates from. All I get is something like "TypeError: undefined not callable". The only way I have been able to track down the error is to try to guess about where the error is coming from and add trace calls to confirm.

I have managed to fix the error at this point, and luckily it happened because of out of order initialization, so it was fairly easy to do, but once I start in the game loop, I think it will be much more difficult to track down any errors without at least a line number telling me where in my code I should be looking.