Hmm, that's strange! I've built with libdispatch on my Debian system before without any problems. I'm a bit unfamiliar with the code here as Lubos implemented the CFStream functions. Hopefully he will chime in with more information. Are you using clang to compile the code? This is generally down by passing the following command "$ CC=clang ./configure && CC=clang make". If I remember correctly, gcd needs clang.
By the way, I apologize for the lack of documentation. I actually have a branch on my computer with a lot of documentation, just haven't committed it, yet.