As per bug 708750 the latest stable version of rabbitmq will not install due to there not existing an elixir version in tree to satisfy it. I've been using =net-misc/rabbitmq-server-3.7.24 on amd64 and its been working fine. Bug 699018 mentions that v3.7 has EOLd, so maybe we want to stabilize a v3.8?
x86 stable
amd64 stable. Closing.