panic: vm_object_vndeallocate: bad object reference count
cpuid = 0
time = 4197251
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe0021330730
vpanic() at vpanic+0x1e0/frame 0xfffffe0021330790
panic() at panic+0x43/frame 0xfffffe00213307f0
vm_object_collapse() at vm_object_collapse/frame 0xfffffe0021330850
vm_map_process_deferred() at vm_map_process_deferred+0xf6/frame 0xfffffe0021330880
vm_map_remove() at vm_map_remove+0x11f/frame 0xfffffe00213308c0
vmspace_exit() at vmspace_exit+0x146/frame 0xfffffe0021330900
exit1() at exit1+0x86c/frame 0xfffffe0021330970
sys_sys_exit() at sys_sys_exit+0xd/frame 0xfffffe0021330980
amd64_syscall() at amd64_syscall+0x436/frame 0xfffffe0021330ab0
fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe0021330ab0
--- syscall (1, FreeBSD ELF64, sys_sys_exit), rip = 0x44f54a, rsp = 0x7fffffffec58, rbp = 0x1 ---
KDB: enter: panic
[ thread pid 1497 tid 100947 ]
Stopped at      kdb_enter+0x6a: movq    $0,kdb_why