Hi Sam, Per our discussion today, unfortunately, it looks like include and includedir support was merged into Heimdal, but hasn't yet made it into a release. It's on the master branch, but is not in 7.4.0. But maybe soon?
Once that code is released, it looks like the way to include a directory of fragments in Heimdal is: includedir /etc/krb5.conf.d include also works, for single files. There are some name restrictions, namely: Only files whose names consist only of alphanumeric characters, hyphen, and underscore, will be parsed, though files ending in ".conf" will also be parsed. -- Russ Allbery (r...@debian.org) <http://www.eyrie.org/~eagle/>