clear-42710 (kernel 6.12.1-1493) fails to boot on fresh install: `VFS: Unable to mount root fs on unknown-block(0,0)``

[jokubasver]

Did a fresh install of the current release 42710 (kernel 6.12.1-1493) and it fails to boot:

Previous current release 42680 with 6.11.6-1477 boots just fine, as did 42700 with 6.11.9-1491. Something changed with the migration to 6.12. Tried the default ext4 and also xfs - no change.

PARTUUID is correct:

The device is a Toshiba WT8-A tablet, which uses a 32GB Samsung MBG4GC eMMC flash.

[bwarden]

This might be an esoteric hardware issue with the eMMC controller. Our best idea is to try playing around with the rootwait kernel boot parameter to see if it just needs some extra time to be ready to access:

        rootwait        [KNL] Wait (indefinitely) for root device to show up.
                        Useful for devices that are detected asynchronously
                        (e.g. USB and MMC devices).

        rootwait=       [KNL] Maximum time (in seconds) to wait for root device
                        to show up before attempting to mount the root
                        filesystem.

[bwarden]

We found an issue introduced in the 6.12 kernel that is most likely the problem here. See discussion in our forum

The fix should be released in a few days.