Comment 2 for bug 211899

This is caused by specifying an invalid report file:
You've given a coredump, but should provide a .crash file instead. Apport then would extract the coredump out of it and run gdb on it (when using the "-g" option, as you've done).

However, apport should not "crash" in this case, but exit with "Cannot open report file" in this case.
I'll attach a branch, which includes this fix.