Unix can impose restrictions on a process, such as the memory size,
the CPU time used, the maximum size of a core dump file, etc. You can
view the preset limits with limit. If the maximum
allowable core dump file size is 0, and you would like to have the
core file, try limit coredumpsize 10000 to set it to 10
MBytes. You can also create core files, which are analyzable by gdb,
by typing C- 
.