Using alternatives system for directories?

[Christian Kastner <ckk@debian.org>]

Hi,

I have a package that ships a number of themes. I'd like to make the
default them configurable system-wide, and the alternatives system
seemed like a good fit.

However, when dh_installalternatives complains when the alternative
isn't a directory:

dh_installalternatives: error: Alternative "<somedir>" for "<somename"
in debian/<somename>.alternatives is a directory

I'm guessing that this isn't a dh_installalternatives limitation but a
limitation of the underlying system bubbling up.

Is my assessment correct? If so, does anyone have a good workaround for
this? My plan B is to otherwise just manage this as a symlink in
/etc/<somepackage>.

Best,
Christian