I can't build gnuradio because the jack maintainers have stopped providing libjack.la and yet portaudio19-dev ships a .la file that has a reference to it. I'm not a libtool expert, but conversation on #debian-devel on IRC suggests that this means that either the jack folks need to reintroduce a dummy libjack.la, or all the jack rdeps (like portaudio19) need to be rebuilt to eliminate the reference. Suggestions? Bdale