For future reference, I had a similar problem; it was asking for Boost::Serialization and Boost::Filesystem. I solved it by passing --with-boost-serialization=boost_serialization and --with-boost-filesystem=boost_filesystem to ./configure. So perhaps --with-boost-signals=boost_signals would have worked for you. (I see that there's also a boost_signals2 available as well, but I have no idea what is what...)