A friend of mine suffered a crash, and since I talked him into
trying netbsd, I thought I'd better check up on his problem. So
here I am with a crash dump -- but how the hell do I get a stack
backtrace out of it. All I have been able to get is:

| asparagus:1 [~/local/tmp3] % gdb netbsd
| GNU gdb 4.17
| ...
| (gdb) target kcore netbsd.0.core
| panic: vrele: ref cnt
| #0  0xf02d6bbc in db_last_command ()
| (gdb) where
| #0  0xf02d6bbc in db_last_command ()
| #1  0x2206000 in ?? ()
| #2  0xf027491f in cpu_reboot ()
| #3  0xf011855a in db_reboot_cmd ()
| #4  0xf0118170 in db_command ()
| #5  0xf01183aa in db_command_loop ()
| #6  0xf011ae82 in db_trap ()
| #7  0xf02720b2 in kdb_trap ()
| #8  0xf027e5b0 in trap ()

  which isn't really saying all that much, is it. Is there a magic
incantation to actually get useful data out the dump?

	mjl