My mistake! I forgot to add the Librarian's Book to the recipes.json for the Carpenter. The files were all there, and I was able to spawn it in. However, at the moment the Librarian has no function as I have not worked out how I want the Librarian to work. In the next update I will be adding in the taxidermist who is taking the statues and impaled heads recipes and will be upgraded from the Carpenter. In this next update I will probably remove the Librarian from the promotion tree unless I have some purpose for them.
I apologize sincerely for this, unless you explicitly want the Librarian in, but he currently cannot even build any items.
I should have a new build up by tonight, featuring the taxidermist, along with several more statue recipes.
Here are some pictures associated with what is being added:
Animals and Creatures Added
Taxidermist Crafting List
In terms of other information, the Mage's fireball should be updated in the current build, as well as I believe further additions to the build I will be uploading.