[Koha] Curious XSLT behavior

[David Liddle]

Greetings all! Our consortium of libraries has been using an XSLT
stylesheet customized back in 2019 for "XSLTDetailsDisplay". I would
like to move this file from:

/usr/share/koha/intranet/htdocs/intranet-tmpl/prog/en/

which is not a path included when 'koha-run-backups' or 'koha-dump' is run, to:

/var/lib/koha/{instance}/xslt/

which is included in those backup routines. According to the manual
for 22.05, which is what we're presently running, there should be no
problem with doing this:

https://koha-community.org/manual/22.05/en/html/staffclientpreferences.html?#xsltresultsdisplay

However, I find the following:
-- When I put the new path in "XSLTDetailsDisplay", the stylesheet is
NOT employed.
-- If I enable that new path in the web server (e.g. "/xslt") and
enter the URL of the file, it is NOT employed. (I verified that it is
reachable through the URL.)
-- If I create a symbolic link from the former path to the current
path, then the stylesheet IS used for display.

My question is: What have I failed to do to make the desired path work directly?

A related observation I have is this: It seems to me that, for
consistency's sake, the XSLT and CSS preferences should function in
the same fashion. Perhaps there is an under-the-hood barrier to this
being the case.

Thank you for reading! I'm looking forward to receiving guidance from
the more experienced.

David Liddle
IT Manager
david.liddle at wycliff.de (just not for this list)

Wycliff e.V., https://wycliff.de
Seminar für Sprache und Kultur, https://spracheundkultur.org/
Internationales Tagungszentrum Karimu, https://karimu.de