telepathy/empathy does not have an informative way to inform people what's going wrong when miss something for jingle to work properly. The following patch will enforce jingle support along the dep chain, make sure everything is built correctly.
Created attachment 164112 [details, diff] telepathy-gabble and farsight patch
a meta package for telepathy connectors would probably be a better idea, look at the gstreamer example, pure binary deps, runtime detected, ... no reason to force the user to recompile the whole package for a protocol flag change.
*** This bug has been marked as a duplicate of bug 206073 ***