[Reproducible-builds] Bug#774983: please use different exit codes for "files differ" and "program crash"

[Helmut Grohne]

Package: debbindiff
Version: 6
User: helmutg at debian.org
Usertags: rebootstrap

Currently, debbindiff uses the exit code 1 to signal the input files
differ. It also uses exit code 1 when it fails with a Python exception.
Please use different exit codes for these situations.

GNU diffutils use exit code 2 for "trouble". Maybe it can be used for
Python exceptions as well?

Helmut