> | [  % gdb cc1 expire/cc1.core ]
> | GDB is free software and you are welcome to distribute copies of it
> |  under certain conditions; type "show copying" to see the conditions.
> | There is absolutely no warranty for GDB; type "show warranty" for details.
> | GDB 4.11 (m68k-netbsd), Copyright 1993 Free Software Foundation, Inc...
> | 
> | "cc1.core" is not a core dump: File format not recognized
> |
> | [ % file expire/cc1.core ]
> | expire/cc1.core: NetBSD/m68k core from 'cc1'

Yes, you are viewing an annoying and unresolved bug with the sun3x port.
Although I did program the pmap, Gordon wrote in the kdump routines, which
are responsible for creating core dumps (among other things.) I haven't
looked into it, but Gordon says that the first page of the core dump file,
which is the u-area of the process, appears to be trashed.  This u-area
is the temporary stack for the process at one point, so it is probably
something linked to the stack.  Strangely enough, if you can get the core
dump to happen over NFS, gdb will accept the file (supposedly.)

-J