The build didn't work for me at first. Workaround: ln -s /usr/lib64/pkgconfig/slv2.pc /usr/lib64/pkgconfig/libslv2.pc emerge ingen stop emerge ingen after src unpack ln -s /usr/lib64 \ /var/tmp/portage/media-sound/ingen-9999/work/ingen-9999/lv2/lv2/osc/.libs ln -s /usr/lib64 \ /var/tmp/portage/media-sound/ingen-9999/work/ingen-9999/redlandmm/src/.libs restart emerge