Break should not even work, and should check if it is a corefile process. But if you do use it: [pmuldoon@localhost frysk_bin]$ ./frysk-core/frysk/bindir/fhpd core.11108 Attached to core file: /home/pmuldoon/frysk_bin/core.11108 (fhpd) break 2 yo dude, double garbage collect! breakpoint 6 deferredbreakpoint 1 deferredbreakpoint 5 deferredbreakpoint 0 deferredbreakpoint 4 deferredbreakpoint 2 deferredbreakpoint 3 deferred