kgdb assert while loading a kernel core

[Weike.Chen at Dell.com]

 Hi all,

 I try to do some debugging for the FreeBSD kernel crash.
 My system is FreeBSD 12. And I have a kernel core file, and while I load it by kgdb. It reports the following error:

 Inferior.c: 287: internal-error: struct inferior *find_inferior_pid(int): Assertion 'pid != 0' failed.

 And I also try the gdb in ports/devel, and got the same error.

 Any workaround for the error?

 Thanks!