Tracking down reasons for segvaulting applications

[Ivo van den Maagdenberg]

My python app ends regularly with a segmentation fault and offers to
save a log by means of a gtk dialog. The actual log contains very
little helpful info. I'd like to know how to catch more fish.

"
Error Signal Information:
        /usr/bin/xyz was interrupted by a Segmentation Fault.

Output Data:
        There was no output

Error Logs:
        There was no error message
"