zfs solaris assert panic in 11.0-ALPHA5 r302256

[Don Lewis]

On 18 Jul, Andriy Gapon wrote:
> On 08/07/2016 07:13, Don Lewis wrote:
>> My package buiding machine just crashed with this panic during a
>> poudriere run:
>> 
>> panic: solaris assert: (dn->dn_phys->dn_nlevels == 0 && db->db_level == 0) || dn->dn_phys->dn_nlevels > db->db_level || dn->dn_next_nlevels[txgoff] > db->db_level || dn->dn_next_nlevels[(tx->tx_txg-1) & TXG_MASK] > db->db_level || dn->dn_next_nlevels[(tx->tx_txg
> 
> Don,
> 
> do you have a crash dump?
> It would be interesting to see a pretty-print of dn, dn->dn_phys, db and
> tx in the frame where the assert is hit.

I do.  Unfortunately kgdb reports that the values of dn and db were
optimized out.