DragonFlyBSD

DragonFly v2.11.0.201.g3ed2f-DEVELOPMENT, HAMMERv1 install.

While installing world into a file image mounted by vnconfig (vn0), the machine
paniced and reboot but I got no dump. I could get this backtrace in dmesg tho:

----- BT in dmesg
disk scheduler: set policy of vn0 to fq
disk scheduler: set policy of vn1 to fq
disk scheduler: set policy of vn2 to fq
disk scheduler: set policy of vn3 to fq
panic: lockmgr: pid -1, not exclusive lock holder thr 0xceef22d8/0xceef14d8
unlocking
cpuid = 0
Trace beginning at frame 0xd6a56af4
panic(ffffffff,0,c06ce3d4,d6a56b28,ceef22d8) at panic+0x198
panic(c06ce3d4,ffffffff,c068d608,ceef22d8,ceef14d8) at panic+0x198
lockmgr(c2e63464,6,d6a56ba8,c03b97b3,c2fba4c4,d6a56b7c,0,ceef22d8,d76d10a0,a100,d88a9538,d6e7ad80,2,d6e7adb8,1000)
at lockmgr+0x40b
brelse(c2e6324c,c0768f18,c2cf4f28,d6a56752,0) at brelse+0x9b7
bpdone(c2e6324c,1,0,c2e6324c) at bpdone+0x8e
biodone(c2e632cc,0,23,0,64042,0,d6978600,22,0,2710,0,4dd3af8a,2fb59) at
biodone+0x1af
fq_completed(c2e6331c,cf220058,c2cf5048,c2e6324c,c2e6324c) at fq_completed+0x1b2
biodone(c2e6331c,d6b070f8,d6a56c98,200,ccae0a40) at biodone+0x18f
vnstrategy(d6a56ce0,ceef22d8,d6978600,c0741e68,cefdccd0) at vnstrategy+0x25a
dev_dstrategy(cefdccd0,c2e6331c,d6978600,d70a3a00,d70a3a00) at dev_dstrategy+0xea
dsched_strategy_async(cf22006c,c2e632cc,c05c8f42,d70a3a00,4dd3af8a) at
dsched_strategy_async+0x54
fq_dispatch(d6978600,c2e632cc,d70a3a00,c06a337d,6) at fq_dispatch+0x5e
fq_dispatcher(d6978600,0,0,0,0) at