Trying to mount root from zfs:sunbuild/root []...

Fatal double fault:
eip = 0x83ee817b
esp = 0x8a6f0fd0
ebp = 0x8a6fl330
cpuid = 6; apic id = 0c
panic: double fault
cpuid = 6
KDB: stack backtrace:
db_trace_seIf_urapper(83bl8fcd,6330203d,0,10000000,83c818f8,...) at db_trace_self_urapper+0x2d/frame 0x83c818c8
kdb_backtrace(83b4aaa4,6,83b4b69f,83c8197c,0,...) at kdb_backtrace+0x30/frame 0x 83c81930
panic(83b4b69f,c,c,6,8a6f1330,...) at panic+0x11f/frame 0x83c81970
dblfault_handler() at cpu_fetch_syscall_args/frame 0x83c81970
--- trap 0x17, eip = 0x83ee817b, esp = 0x8a6f0fd0, ebp = 0x8a6fl330 ---
vdev_queue_io_to_issue(8b8c9b70,8ba515b8,83f9c6f4,307,8b8c9bc0,...) at vdev_queue_io_to_issue+0x2b/frame 0x8a6f1330
vdev_queue_io(8ba515b8,8b9ba894,8ba515b8,10,1,...) at vdev_queue_io+0xf9/frame 0 x8a6f1370
zio_vdev_io_start(8ba515b8,8b8c9800,16510600,2,8b9ba894,...) at zio_udeu_io_star t+0x442/frame 0x8a6fl3cc
zio_executeC8ba515b8,8b9ba8f8,8b8c9800,16110600,2,...) at zio_execute+0xl3d/fram e 0x8a6fl40c
vdev_mirror_io_start(8b9ba894,10,8b9ba894,l,20d,...) at vdev_mirror_io_start+0x3 17/frame 0x8a6fl470
zio_vdev_io_start(8b9ba894,8aa76620,83f0389a,8b9ba978,8b8decd8,.. .) at zio_udeu_ io_start+0x298/frame 0x8a6fl4cc
zio_execute(8b9ba89^1,8b885000,8bf50000,8b83da00,200,...) at zio_execute+0xl3d/fr
zio_execute(8b9ba894,8b885000,8bf50000,8b83da00,200,...) at zio_execute+0xl3d/fr ane 0x8a6fl50c
spa_load_v0rify_cb(8b885000,0,8bf50000,8a6f1700,8bf49a00,...) at spa_load_uerify _cb+0xlc8/frane 0x8a6fl558
trauers0_uisitbpC8bf50000,8a6f1700,8bf49a40,8306c720,8a6f16fc,...) at traverse_v isitbp+0x266/frane 0x8a6fl678
trav0rs0_visitbp(8bf49a40,8a6fI860,8bf40000,8306c720,8a6f181c,...) at traverse_v isitbp+0xca2/frame 0x8a6fl798
traverse_v is itbp C8bf40000,8a6f1940,8bf3c000,8306c720,8a6f193c__) at traverse_v
isitbp+0xll93/fram0 0x8a6fl8b8
trau0rs0_uisitbpC8bf3c000,8a6fla60,8bf38000,8306c720,8a6fla5c,...) at traverse_v isitbp+0xca2/frame 0x8a6fl9d8
trau0rs0_u is itbp C8bf38000,8a6flb80,8bf34000,83e6c720,8a6flb7c ) at traverse_v
isitbp+0xca2/fram0 0x8a6flaf8
traverse_visitbp(8bf34000,8a6flca0,8bf30000,83e6c720,8a6flc9c,...) at traverse_v isitbp+0xca2/fram0 0x8a6flcl8
trauers0_uisitbpC8bf30000,8a6fldc0,8bf2c000,83e6c720,8a6fldbc,...) at traverse_v isitbp+0xca2/fram0 0x8a6fld38
traverse_visitbp(8bf2c000,8a6fIee0,8bc40840,83e6c720,8a6fledc,...) at traverse_v isitbp+0xca2/fram0 0x8a6fl058
traverse_visitbp(8bc40840,8a6f2040,8bclda80,83e6c720,8a6flffc,...) at traverse_v isitbp+0xca2/fram0 0x8a6flf78
traverse_visitbp(8bclda80,8a6f20d8,8bclda80,83e6c720,8a6f20d0,...) at traverse_v isitbp+0x72f/fram0 0x8a6f2098
trav0rs0_inpl(93,0,8bclda80,Ic2c6c,0,...) at traverse_impl+0x321/frame 0x8a6f217 0
trav0rs0_pool(8b885000,Ic2c6c,0,5,830d09c0,...) at traverse_pool+0xld9/frame 0x8 a6f2210
spa_load(0,l,8a6f2394,8b9e4080,8____) at spa_load+0x213f/frame 0x8a6f2318
spa_load(0,0,83f99f4e,2,24,...) at spa_load+0xl3ea/frame 0x8a6f2420
a6f2210
spa_load(0,l,8a6f2394,8b9e4080,8_____) at spa_load+0x213f/frame 0x8a6f2318
spa_load(0,0,83f99f4e,2,24,...) at spa_load+0xl3ea/frame 0x8a6f2420 spa_load_best(0,ffffffff,ffffffff,l,843dc240,...) at spa_load_best+0x7f/frame 0x 8a6f2478
spa_open_common(83f90b62,0,0,8a6f2504,83ea9d02,...) at spa_open_common+0xllb/fra me 0x8a6f24cc
Spa_open(8b81ded0,8a6f24f4,83f90b62,0,8b897000,...) at spa_open+0x27/frame 0x8a6 f24e0
dsl_pool_hoId(8b81ded0,83f90b62,8a6f2520,8aa76620,8a6f2530_____) at dsl_pool_hoId
+0x22/frame 0x8a6f2504
dmu_objset_oun(8b81ded0,2,I,8b897000,8a6f2578,...) at dmu_objset_oun+0x23/frame 0x8a6f2530
zfsvfs_create(8b81ded0,8a6f264c,83fa0f7a,6bc,0,...) at zfsvfs_create+0x4c/frame 0x8a6f2590
zfs_mount(8b861d20,83fab674,8b867680,8aa74d00,8b81def0______) at zfs_mount+0x3f2/f
rame 0x8a6f2768
vfs_donmount(8aa76620,4000,0,8a6f2988,8b867700, . . .) at vfs_donmount+0xcaf/frame 0x8a6f2970
kernel_mountC8b81df40,4000,0,0,5,...) at kernel_mount+0x52/frame 0x8a6f29b0 parse_mount(8b81df40,83b9ae28,0,1,0,...) at parse_mount+0x660/frame 0x8a6f2a88 vfs_mountroot(83cc2084,8aa76620,0,0,0,...) at vfs_mountroot+0xac6/frame 0x8a6f2c 60
start_init(0,8a6f2d08,0,0,83757ab0,...) at start_init+0x5e/frame 0x8a6f2cd0 fork_ex it C83757ab0,0,8a6f2d08) at fork_exit+0x67/frame 0x8a6f2cf4 fork_trampoline() at fork_trampoline+0x8/frame 0x8a6f2cf4
 trap 0, eip = 0, esp = 0x8a6f2d40, ebp = 0 ------
KDB: enter: panic [ thread pid 1 tid 100001 1
Stopped at kdb_enter+0x3d: movl $0,kdb_uhy