panic: pmap active 0xfffff8002d2ae9f8

Hi,

I have a system running CURRENT at r266925 from May 31.

While doing some software builds using poudriere, the system
panicked.  Unfortunately this system was not configured with
swap space, so I cannot do a kernel dump.

The system is currently at the ddb prompt.
Here is the backtrace:


Here is the backtrace from ddb:

panic: pmap active 0xfffff8002d2ae9f8
cpuid = 5
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame
0xfffffe183958a7d0
kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe183958a880
vpanic() at vpanic+0x126/frame 0xfffffe183958a8c0
kassert_panic() at kassert_panic+0x139/frame 0xfffffe183958a930
pmap_remove_pages() at pmap_remove_pages+0x8c/frame 0xfffffe183958aa20
vmspace_exit() at vmspace_exit+0xa1/frame 0xfffffe183958aa60
exit1() at exit1+0x541/frame 0xfffffe183958aad0
sys_sys_exit() at sys_sys_exit+0xe/frame 0xfffffe183958aae0
amd64_syscall() at amd64_syscall+0x25a/frame 0xfffffe183958abf0
Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfffffe183958abf0
--- syscall (1, FreeBSD ELF64, sys_sys_exit), rip - 0x800b195aa, rsp -
0x7ffffffe3e8, rbp = 0x7ffffffffe400
KDB: enter: panic
[ thread pid 94762 tid 101570 ]
Stopped at       kdb_enter+0x3e: movq        $0.kdb_why
db>


Is this a known problem?
Are there other commands I should type at the ddb prompt?
--
Craig