attaching gdb to stopexit'ed process (was: unconditional core dump on exit?)

[Edgar Fuß]

EF> Is there a way to make a process dump core on exit no matter what?
EF> I have a deamon dying (or whatever) from time to time with no trace to the 
EF> cause and guess a backtrace from a dump would help.
KR> Start under a debugger, break on 'exit'.
I tried to set proc.$pid.stopexit, but when I attach to the stopped process 
via gdb, it exits. Is that a bug?