brew update
brew versions FORMULA
cd `brew --prefix`
git checkout HASH Library/Formula/FORMULA.rb # use output of "brew versions"
brew install FORMULA
brew switch FORMULA VERSION
git checkout -- Library/Formula/FORMULA.rb # reset formula
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## Example: Using Subversion 1.6.17
#
# $ brew versions subversion
# 1.7.3 git checkout f8bf2f3 /usr/local/Library/Formula/subversion.rb
# 1.7.2 git checkout d89bf83 /usr/local/Library/Formula/subversion.rb
# 1.6.17 git checkout 6e2d550 /usr/local/Library/Formula/subversion.rb
# 1.6.16 git checkout 83ed494 /usr/local/Library/Formula/subversion.rb
# 1.6.15 git checkout 809a18a /usr/local/Library/Formula/subversion.rb
# 1.6.13 git checkout 7871a99 /usr/local/Library/Formula/subversion.rb
# 1.6.12 git checkout c99b3ac /usr/local/Library/Formula/subversion.rb
# 1.6.6 git checkout 8774131 /usr/local/Library/Formula/subversion.rb
# 1.6.5 git checkout a82e823 /usr/local/Library/Formula/subversion.rb
# 1.6.3 git checkout 6b6d369 /usr/local/Library/Formula/subversion.rb
# $ cd `brew --prefix`
# $ git checkout 6e2d550 /usr/local/Library/Formula/subversion.rb
# $ brew install subversion
# $ brew switch subversion 1.6.17
# $ git checkout -- Library/Formula/subversion.rb
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Reference： https://gist.github.com/gcatlin/1847248