[$] Debian ponders filesystem-image forward compatibility

Developers who build distributions often (but not always) put considerableeffort into backward compatibility, ensuring, for example, that a programbuilt for one release will continue to run on later releases. Forwardcompatibility, 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, butit still tends to be seen as something that is better to not break ifpossible. So it is not surprising that an issue affecting theforward-compatibility of ext4 filesystems built for the upcomingDebian 12 ("bookworm") release has generated a fair amount ofdiscussion, even if the number of affected users is likely to be small.