After hacking around for a while, I figured I'd just use the libraries
PI uses that are installed on my system rather than those that are
packaged with PI (bin/lib). Provided you can work out the deps yourself,
bearing in mind I had to build some libraries from source as they
weren't contained in my distro's repo, this should work for all you
other rolling release Linux/BSD users out there.
The fix is relatively straightforward, if you don't consider the symlink
creation and compiling libraries from source. Edit the PixInsight.sh
bash script in the PI directory and alter the line
LD_LIBRARY_PATH=$dirname/lib:$dirname
so that it reads
LD_LIBRARY_PATH=$dirname
For any novice Linux users out there, this will link against libraries
found elsewhere in your $PATH rather than those in the PI lib
directory.
That's it. After all the other hackery, this is what finally made it work.
It might be worthwhile to have argument parsing in this script so that
you could specify which set of libraries you'd like to use. Now, onward
with PI-foo!