[$] Debian ponders filesystem-image forward compatibility

Developers who build distributions often (but not always) put considerable
effort into backward compatibility, ensuring, for example, that a program
built for one release will continue to run on later releases. Forward
compatibility, where it is possible to move a program (or other artifact)
from a more recent release to an older one, can be less of a concern, but
it still tends to be seen as something that is better to not break if
possible. So it is not surprising that an issue affecting the
forward-compatibility of ext4 filesystems built for the upcoming
Debian 12 ('bookworm') release has generated a fair amount of
discussion, even if the number of affected users is likely to be small.