If you recieve something like {could_not_start,rabbit,{previous_upgrade_failed,{rabbit,start,[normal,[]]}}}
, searching for could_not_start
didn't provide me with much help.
For rabbitmq: stable 3.5.3 this is located at /usr/local/var/lib/rabbitmq/mnesia/
.
Simply rm -rf *
to remove all of it's contents.
Note this will remove all your messages, but in development, this wasn't a concern.