https://gitweb.gentoo.org/repo/gentoo.git/tree/media-sound/audacity/audacity-2.1.3-r1.ebuild#n30 should be changed to flac? ( >=media-libs/flac-1.3.1[cxx] ) Resolution to failed compilation on Gentoo with flac-1.3.0 with same error as in http://audacity.238276.n2.nabble.com/Audacity-2-1-3rc3-finds-but-ignores-system-ffmpeg-libs-tp7578709p7578746.html .
Have implemented this as a revbump via https://github.com/gentoo/gentoo/pull/5617 but it could equally be a patch to -r1 if requested.
Removed richard@audacityteam because it does not concern upstream
Seems to be fixed in all audacity versions currently being in our package repo...