I built glib-2.38.2 on OS X 10.8, and my "gdb" is /usr/bin/gdb as supplied by Apple as part of XCode-5.1.1. Running 'make check' in the tests subdir yields:

PASS: run-assert-msg-test.sh

However, 'ps' reveals a zombie assert-msg-test process. I have separate user account for build sandboxing, and simply running that .sh directly:

 sudo -u fink-bld ./run-assert-msg-test.sh

leaves one new zombie every time. Looks like the gdb session aborts before terminating the sublaunched process. Adding a "quit" to the end of assert-msg-test.gdb lets me run that sudo command repeatedly with no new zombies created.