re: bitcoin / doc / build-unix.md
The documentation is missing one dependency. You also need protobuf-compiler, not just libprotobuf-dev
So the line under QT compilation should be
apt-get install libqt4-dev libprotobuf-dev protobuf-compiler
Failure to do so will spew an error about not being able to find paymentrequest.pb.h
Sorry if I should have forked and then requested a merge or something more technical. I'm new to this and am unsure of protocol. But since it's a relatively simple documentation I thought this would be easier.
Thanks.