package dev-ruby/listen installs /usr/bin/listen which is also installed by media-radio/ax25-apps
I can easily add an DEPEND blocker like we did for media-sound/listen but the other side had to be done by the ruby team.
I've added a blocker to dev-ruby/listen for both media-radio/ax25 and media-sound/listen (bug 247811). I'll leave the bug open until a better solution is found.
Just add the blocker for dev-ruby/listen from my side also. Thanks Hans.