Installing RabbitMQ In Ubuntu 12.04 LTS

The installation instructions can largely be found at here, but in case you run into a small hiccup that looks like:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.

Since you only requested a single operation it is extremely likely that
the package is simply not installable and a bug report against
that package should be filed.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
rabbitmq-server: Depends: erlang-nox (>= 1:12.b.3) but 1:11.b.5dfsg-11 is to be     installed
E: Broken packages

the trick is to remove any existing installation of rabbitmq and erlang-nox.

Here are my installation steps, using RabbitMQ APT repository:

1. Add the following line to your /etc/apt/sources.list: deb http://www.rabbitmq.com/debian/ testing main
2. Add RabbitMQ public key to trusted key list: wget http://www.rabbitmq.com/rabbitmq-signing-key-public.asc, then sudo apt-key add rabbitmq-signing-key-public.asc
3. Run apt-get update.
4. Uninstall existing RabbitMQ installation: sudo apt-get remove rabbitmq-server
5. Uninstall existing erlang-nox: sudo apt-get remove erlang-nox
6. Re-install latest RabbitMQ: sudo apt-get install rabbitmq-server

Original post can be found here