Comment # 1 on bug 1127997 from Ignaz Forster

The reason why the boot failed is probably because of a missing /var partition
(causing /etc's mount to fail due to missing directories). Otherwise this
system would probably have worked, though is wouldn't have been possible to
update or modify it (without manual steps at least).

On a regular installation this setup doesn't make a lot of sense�. I'd thus say
option 1 (only allowing Btrfs for the root file system) is the correct
resolution here. But more importantly on a read-only root file system it should
be ensured that a separate /var mount exists before continuing installation.

� Pure read-only images are probably useful for cloud images, as those can be
recreated from scratch each time. But those aren't created with YasT anyway.