media-sound/ardour with doc flag needs app-doc/doxygen being compiled with dot flag. Merging media-sound/ardour-3.0 with doc useflag enabled fails. Adding app-doc/doxygen dot in /etc/portage/package.use solves the problem. suggestion : changing the Depend dection in the ebuild (?) : DEPEND="${RDEPEND} virtual/pkgconfig nls? ( sys-devel/gettext ) doc? ( app-doc/doxygen[dot] )"
You are right, I added it to the ebuild without a revbump as it wouldn't compile for affected users... Thanks for reporting! :-)