I'm getting a NoClassDefFound when loading a pack: https://gist.github.com/codetaylor/015e9bc1eaec0c45867942dcfdfaeff6

It looks the same as #1, but I do have Bookshelf-1.12.2-2.3.577.

Peeking in the lib clearly shows the class is there:

I'm at a loss...

I noticed there aren't any dependencies listed for bookshelf, could the mod be loading before the lib?

Yeah, there is a load order issue with the mod.

I thought I had already fixed this issue, and it turns out I had. You are using an outdated version of the mod (1.0.3 has the fix). You also linked to the master branch but I built off the 1.12.2 branch which has the fix.

Oops! Thanks for your time :)