OpenChess

I am interested in using the Polyglot adapter to play opening books on Stockfish's behalf. I am further interested in customizing polyglot to play variants as I have started to do so here on Github.

I have forgotten how I managed to the polyglot repository in the first place, and from the looks of it I cloned a 2-year-old "master" branch and I am missing the "learn" branch. Please advise how I may clone the polyglot adapter. Thanks in advance!

IIRC you can import other branches from an external repository with the command 'git pull BRANCHNAME'.

Note that there already exists a 'variant-agnostic' WB adapter for UCI engines called UCI2WB, which can be used for arbitrary variants, and even understands the most common UCI dialects (UCCI and USI). It doesn't handle opening books, however. I mention it because it might be a more convenient starting point for what you want.