totem in gdb crashes -current

I can crash my -current/amd64 machine each time by doing:

gdb `which totem`
r

The machine reboots with no information in log files or dropping down
into the debugger.  Kernel built with:

makeoptions     DEBUG=-g                # Build kernel with gdb(1) debug
symbols

options         SCHED_4BSD              # 4BSD scheduler
options         PREEMPTION              # Enable kernel thread
preemption

options         ADAPTIVE_GIANT          # Giant mutex is adaptive.

# Debugging for use in -current
options         KDB                     # Enable kernel debugger
support.
options         DDB                     # Support DDB.
options         GDB                     # Support remote GDB.

no invariants or witness set except

options         WITNESS_SKIPSPIN        # Don't run witness on spinlocks
for speed