Improve truncated backtrace format for python and core

[mhabrnal]

Old core truncated backtrace format:

1 crash in /usr/bin/will_segfault

2 varargs in /usr/bin/will_segfault

3 f in /usr/bin/will_segfault

4 callback in /usr/bin/will_segfault

5 call_me_back in /usr/lib64/libwillcrash.so.0.0.0

New core truncated backtrace format:

1 [will_segfault] crash

2 [will_segfault] varargs

3 [will_segfault] f

4 [will_segfault] callback

5 [libwillcrash.so.0.0.0] call_me_back

Old python truncated backtrace format:

1 crash in /home/mhabrnal/a.py:4

2 a in /home/mhabrnal/a.py:7

3 recursion in /home/mhabrnal/a.py:13

4 recursion in /home/mhabrnal/a.py:11

5 recursion in /home/mhabrnal/a.py:11

New python truncated backtrace format:

1 [/home/mhabrnal/a.py:4] crash

2 [/home/mhabrnal/a.py:7] a

3 [/home/mhabrnal/a.py:13] recursion

4 [/home/mhabrnal/a.py:11] recursion

5 [/home/mhabrnal/a.py:11] recursion

Basename is in Python truncated backtraces along with its path because there can be init.py file and we want to know where is the file placed.

Fixes: #253

Signed-off-by: Matej Habrnal mhabrnal@redhat.com

[mkutlak]

retest this please

[mkutlak]

Rebased to fix conflict in test, otherwise LGTM.

Thank you @mhabrnal