Find all available versions of a homebrew formula and resove "fatal: '/usr/local/Library/Formula/XXX.rb' is outside repository" error

Find all versions of a formula

# Allways a good idea to sync with the formular repository first
alex$ brew update

# List available version
alex$ brew versions zmq
3.2.2    git checkout ab8de4b /usr/local/Library/Formula/zeromq.rb
2.2.0    git checkout 6a2e6ef /usr/local/Library/Formula/zeromq.rb
2.1.11   git checkout 497b13a /usr/local/Library/Formula/zeromq.rb
2.1.10   git checkout 4c8ed3a /usr/local/Library/Formula/zeromq.rb
2.1.9    git checkout 381c97f /usr/local/Library/Formula/zeromq.rb
2.1.7    git checkout ed41f79 /usr/local/Library/Formula/zeromq.rb
2.1.8    git checkout 8e045d5 /usr/local/Library/Formula/zeromq.rb
2.1.6    git checkout 460a168 /usr/local/Library/Formula/zeromq.rb
2.1.4    git checkout 83ed494 /usr/local/Library/Formula/zeromq.rb
2.1.3    git checkout f4a925d /usr/local/Library/Formula/zeromq.rb
2.1.2    git checkout 3017b39 /usr/local/Library/Formula/zeromq.rb
2.1.1    git checkout 0476235 /usr/local/Library/Formula/zeromq.rb
2.0.10   git checkout 00e1ae3 /usr/local/Library/Formula/zeromq.rb
2.0.9    git checkout 0527b6f /usr/local/Library/Formula/zeromq.rb
2.0.8    git checkout 1f252bf /usr/local/Library/Formula/zeromq.rb
2.0.7    git checkout ce8d2f5 /usr/local/Library/Formula/zeromq.rb

Install a specific formular

# Lets pick version 3.2.2 of the zmq formula
git checkout ab8de4b /usr/local/Library/Formula/zeromq.rb

# Then install the formula
alex$ brew install zmq
==> Installing zeromq dependency: pkg-config
==> Downloading https://downloads.sf.net/project/machomebrew/Bottles/pkg-config-
.....

Troubleshooting

# Troubleshooting
# If you get something like this

alex$ git checkout ab8de4b /usr/local/Library/Formula/zeromq.rb
fatal: '/usr/local/Library/Formula/zeromq.rb' is outside repository

# You might have local modification of that formular. 
# This is how you can check it
alex$ cd /usr/local/Library/Formula/
itiny:Formula alex$ git status
# On branch master
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#  modified:   zeromq.rb
#

# Revert your modifications
git checkout zeromq.rb

# Now you should be able to switch to the specific version e.g. for version 3.2.2
git checkout ab8de4b /usr/local/Library/Formula/zeromq.rb