I have packaged an application for Debian using Debhelper. The application's config file is located under /opt/{package}/releases/default/ instead of /etc/{package}/ and cannot be moved easily. Up until recently all that was required to mark this config file as a conffile was to include it in the packaging file debian/{package}.conffiles. This had the desired effect that apt/dpkg would detect local changes to the config file upon upgrade and handle it in a smart way instead of clobbering the local changes with the packaged version.
After upgrading the package tooling to a newer version I no longer enjoy this benefit. The man page dh_installdeb(1) reads:
{package}.conffiles:
Historically, this file was needed to manually mark files files as
conffiles. However, it has become de facto obsolete since debhelper
automatically computed which files should be marked as conffiles.
Further, from the Debian New Maintainers' Guide:
5.3. conffiles
dh_installdeb(1) automatically flags any files under the /etc directory
as conffiles, so if your program only has conffiles there you do not
need to specify them in this file. For most package types, the only place
conffiles should ever be is under /etc, and so this file doesn't need to exist.
My question is how do I achieve the old behaviour by keeping the config file under /opt/?
