This has been *such* a PITA, but I think I just got The Public Radio's EAGLE libraries onto Github in a way that makes sense.
The goal: To have everyone be able to access all of the parts that we use on The Public Radio, no matter where they are or who created the package/symbol/part, by just syncing the Github repo.
Our Github page now has one active repo (Embedded_Hardware) - and two for firmware & firmware libraries that are mostly inactive for now. Within Embedded_Hardware are two big subdirectories (EAGLE_CAD and EAGLE_lbr), plus an ARCHIVE and a place for us to put production files (Gerbers, etc).
Within EAGLE_lbr, there is one EAGLE CAD library file - PR_Parts_Library.lbr. From now on, that will be the default library for all packages, symbols, and parts that we create or modify for use in The Public Radio.
In order to make this all work, you need to add the local directory that you sync to Github to your EAGLE Libraries search path. I keep our Github repositories at ~/Documents/The-Public-Radio, so I added :$HOME/Documents/The-Public-Radio/Embedded_Hardware/EAGLE_lbr to the end of my Libraries search path:
And now the EAGLE libraries show up just fine!
Lastly, I opened up our .brd and .sch and went through all the parts I had created. I drew the speaker, potentiometer, antenna hole and batteries. The .brd and .sch included copies of those parts that came from a library on my local disc, so first I had to find those parts and copy them to our new shared library. Then I went into the .brd and .sch and swapped the old versions of those parts for the new ones.
Anyone else who's working on the project right now (that'd be Zach and Andy) can do the same with any of the footprints that they created. And anyone who's hoping to make their own (not sure why they would, but who am I to ask) can grab the entire Embedded_Hardware repository and modify packages to their heart's delight. If you do so and find a mistake we've made, please let me know - we're happy to take any pull requests that improve on our design!