Another clue: After gimp crashed in gdb, I couldn't type anything in any xterminal.
However, pressing ctl-alt-F1, to go to an old school console, worked. That let me kill gdb's process and fix my key baord. Another clue, maybe: gdb reported Thread 1 "gimp" received signal SIGSEGV, Segmentation fault. 0xb7010f49 in signal_emit_unlocked_R (node=node@entry=0x82e7b2a0, detail=detail@entry=0, instance=instance@entry=0x80ba2288, emission_return=0x0, instance_and_params=0xbf8000d0) at ../../../gobject/gsignal.c:3501 3501 ../../../gobject/gsignal.c: No such file or directory. So, Kingsley -- Time is the fire in which we all burn.