After upgrading from r344695 to r347946 (March 1, 2019 -> May 17, 2019) the loader panics with the summary message during startup. The problem occurs with both loader_lua and loader_4th. Both loaders worked correctly prior to the upgrade.
Is it possible to attach a screenshot of the panic?
I'm hoping it contains a panic backtrace which may provide more info.
If you can alternatively generate a backtrace at that point and include that as an attachment, that would be great
Sadly, the entire content of the message produced by the loader panic is the single line I reproduced (well, there's also a '--> Press a key on the console to reboot <--). If you tell me how, I'll be happy to try to produce a backtrace.
Other reports on -stable indicate this is affecting other people.
Somewhere between r348491 and r349154 this problem disappeared.
The only change I see that might have corrected it was 348867:
MFC r342747 (mmacy): zfsboot: support newer ZFS versions.
342747 is documented as:
zfsboot: support newer ZFS versions
declare v3 objset size/layout to fix userboot and possibly other loader issues
- fix for userboot assertion failure in zfs_dev_close in free due to out of bounds write
- fix for zfs_alloc / zfs_free mismatch assertion failure when booting GPT on BIOS
In any event /boot/loader compiled before this change fails and subsequent to it works.
I'm closing the report since the bug has likely been fixed.