problem with amd64 minidump

Not sure if this is some local issue or a problem in FreeBSD code.
I remember minidumps working perfectly well for me, but now I can not get data
from them.
Example:
dmesg -M /var/crash/vmcore.4
dmesg: _kvm_vatop: direct map address 0xffffff012fffffe0 not in minidump
dmesg: kvm_read: invalid address (0xffffff012fffffe0)

Needless to say kgdb refuses to work with that core too.

With kgdb on live system I can access that address:
(gdb) x/a 0xffffff012fffffe0
0xffffff012fffffe0:     0xffffff012ffe0000

Looks like perhaps we do not include something that we should into the dump?
Thanks!
-- 
Andriy Gapon