As said in bug #168883 , install or upgrade of/to media-plugins/audacious-plugins-1.3.0_rc2 should be impossible when media-plugins/audacious-plugins-ugly-1.2.0 installed. I think the best way for me would be a block when =<media-plugins/audacious-plugins-ugly-1.2.0 detected.
*** Bug 168886 has been marked as a duplicate of this bug. ***
Please don't file triplicate bugs about identical issue. *** This bug has been marked as a duplicate of bug 168883 ***