Looks like Luke-jr has removed jansson (jansson is included and built in cgminer) from bfgminer. When Luke-jr copied/ripped-off cgminer he must have removed it and now you will need libjansson installed to compile successfully.

Looks like he decided to copy my documentation (windows-build.txt) and not modify it when he makes changes to his copied/ripped-off code.

I will not be updating the build instructions for cgminer or bfgminer in the future as only one donation has ever been made. It simply is not worth my time to keep it up to date (especially since I will be going to Linux only when my ASIC devices arrive).

I make references to "copied/ripped-off" but actually the term is forked. Luke-jr likes to claim that he was the original author and that cgminer was forked from his code, but that simply is not the case. Luke-jr did contribute code to cgminer and then forked the project to bfgminer.