λ ~ → ulimit -c unlimited λ ~ → echo 'a\nb\nc' | strace dmenu &> dmenu.strace.txt λ ~ → gdb -q `which dmenu` dmenu.coredump Reading symbols from /usr/sbin/dmenu...(no debugging symbols found)...done. [New LWP 7055] [Thread debugging using libthread_db enabled] Using host libthread_db library "/usr/lib/libthread_db.so.1". Core was generated by `dmenu'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x00007f8acc401560 in XmbLookupString () from /usr/lib/libX11.so.6 (gdb) bt full #0 0x00007f8acc401560 in XmbLookupString () from /usr/lib/libX11.so.6 No symbol table info available. #1 0x00005559ee2108b3 in ?? () No symbol table info available. #2 0x00007f8acbdb3223 in __libc_start_main () from /usr/lib/libc.so.6 No symbol table info available. #3 0x00005559ee21187e in ?? () No symbol table info available. (gdb) quit