Well, it is not Scratchbox-only problem. On other production systems its usually /etc and /var/log although logrotate with compression mitigates the latter, and manual backing up the former. The other bugger is /home/$USER/.*

The last time I screwed up Scratchbox was when suddenly half my binaries were gone in my targets. They were in ls but when I tried to execute them I got command not found. This was not related to $PATH. OK, I did something macabre (replaced qemu-arm binary), but that shouldn't have this effect and I reverted the change.

It could also be the case my SSD is dying, or because I had kernel panic. Heck, it could even been due to OOM killer. But there is nothing in /lost+found.

Another time I did not use /usr/local and installed dependencies, or the packages from Debian overlapped. Or I changed a Makefile and forgot to back it up first.

No matter what I want some kind of data consistency, and I also like to go back to a general vanilla starting point to evade race conditions where stuff is non-default. VMs do provide snapshots, but also overhead, and I can't run one at the moment on my target machine.

Without using a versioning filesystem do you think GIT can be used, with OK performance, to have good versioning including a whole target? Would gitfs work?

Ideally, one could just execute less filename.txt;2 which reads the last version of the filename before it was modified to its current incarnation.

The only suitable, stable alternative I found thus far seems to be kernel-space filesystem called NILFS. I'll try it and report.