gdb cannot read kernel crash dump

[Julio Merino <jmmv%julipedia.org@localhost>]

Hello,

My virtual machine running amd64 -current just crashed and rebooted
while building a set of packages.  I found a crash dump in /var/crash
and attempted to load it with gdb (after gunzipping it, of course), but
gdb complains:

netbsd# gdb -q netbsd.1 netbsd.1.core
(no debugging symbols found)
"/var/crash/netbsd.1.core" is not a core dump: File format not recognized
(gdb)

Might this have been caused by gcc 4.5 changes?

Thanks.