Error starting Rabbitmq on MacOS

After having problems with my Homebrew I had to reinstall a few things. A month or so later I found I had forgotten to reinstall RabbitMq so I did the usual:

brew install rabbitmq

I went to:

cd /usr/local/sbin

Then I started rabbitmq:

./rabbitmq-server 

which resulted in an error:

JMBP:sbin johnroberts$ ./rabbitmq-server 

  ##  ##

  ##  ##      RabbitMQ 3.7.14. Copyright (C) 2007-2019 Pivotal Software, Inc.

  ##########  Licensed under the MPL.  See https://www.rabbitmq.com/

  ######  ##

  ##########  Logs: /usr/local/var/log/rabbitmq/rabbit@localhost.log

                    /usr/local/var/log/rabbitmq/rabbit@localhost_upgrade.log

              Starting broker...

{"Kernel pid terminated",application_controller,"{application_start_failure,rabbit,{{schema_integrity_check_failed,[{table_attributes_mismatch,rabbit_exchange,[name,type,durable,auto_delete,internal,arguments,scratches,policy,operator_policy,decorators,options],[name,type,durable,auto_delete,internal,arguments]}]},{rabbit,start,[normal,[]]}}}"}

Kernel pid terminated (application_controller) ({application_start_failure,rabbit,{{schema_integrity_check_failed,[{table_attributes_mismatch,rabbit_exchange,[name,type,durable,auto_delete,internal,ar

Crash dump is being written to: /usr/local/var/log/rabbitmq/erl_crash.dump...done

Looking at $PATH

echo $PATH

I noticed rabbitmq was not in there so I added it.

Still no good!

I then noticed that the error referred to a table and that the error log file referred to a database directory:

 database dir   : /usr/local/var/lib/rabbitmq/mnesia/rabbit@localhost

I had a hunch that removing rabbitmq the first time probably didn't remove the database directory and the new install was probably incompatible with what was in there.

So I uninstalled rabbitmq using

 brew uninstall rabbitmq

and noticed the db directory was still there.
So I removed the directory.

Then,
Reinstalled rabbitmq.
Started it.
And jolly good news.

  ##  ##

  ##  ##      RabbitMQ 3.7.14. Copyright (C) 2007-2019 Pivotal Software, Inc.

  ##########  Licensed under the MPL.  See https://www.rabbitmq.com/

  ######  ##

  ##########  Logs: /usr/local/var/log/rabbitmq/rabbit@localhost.log

                    /usr/local/var/log/rabbitmq/rabbit@localhost_upgrade.log

              Starting broker...

 completed with 7 plugins.

thanks