Dear Maintainer,

with bacula 15 the new fast also better compression zstd was introduced for
the fileset directive.
Also the faster xxh3 signature directive was been added.

I tried to use them and silently no failures was been shown.
That is is not running as expected is shown in the job details
after the job is finished:

13-Jun 14:17 backup-fd JobId 84970: Error: crypto.c:655 Unsupported digest type: 7
13-Jun 14:17 backup-fd JobId 84970: Warning: XXH3_64 digest digest initialization failed
..
   Software Compression:   None
...

Maybe both are included from debian maintainers?

I've started a discussion on

<https://lists.debian.org/debian-user-german/2026/06/msg00021.html>

retitle 1139918 bacula-fd: New xxhash signatures and zstd compression does not work

Looks like xxh3 not a community based signature.
By the way using xxhash does not work, too:

*me
14-Jun 15:15 backup-dir: ERROR in inc_conf.c:350 Config error: Expected a FileSet option keyword, got:xxhash:
             : line 33, col 30 of file /etc/bacula/fileset.conf
             signature = xxhash;

14-Jun 15:15 backup-dir: ERROR in inc_conf.c:350 Config error: Expected a FileSet option keyword, got:xxhash:
             : line 44, col 30 of file /etc/bacula/fileset.conf
             signature = xxhash;

The ZSTD issue is an upstream bug, which I fixed in:

https://gitlab.bacula.org/bacula-community-edition/bacula-community/-/work_items/2755

There has not been an upstream release since then, though.

The patch in that upstream bug (fix-zstd-detection.diff, attached)
should be usable in the Debian build, if desired. That's how I tested it
originally.