Install ruby-head (1.9.3) and patch `require`

install_ruby_patch.sh

# Install ruby-head (1.9.3) and patch `require`
#
# using: rvm and homebrew

# update dependencies
brew install libyaml readline

# update rvm
rvm get head
rvm reload


cd $PROJECT

# log old bootup time
time ruby -e 'require "./config/environment"'

# install patched ruby version
curl https://gist.github.com/raw/996418/e2b346fbadeed458506fc69ca213ad96d1d08c3e/require-performance-fix-r31758.patch > /tmp/require-performance-fix.patch
rvm install ruby-head --patch /tmp/require-performance-fix.patch -n patched --with-libyaml-dir=/usr/local --with-readline-dir=/usr/local/

# use new ruby version and install all dependecies
rvm use ruby-head-patched
gem install bundler
gem install gherkin --version 2.3.2 -- --with-cflags="-std=c99"
bundle

# log old bootup time
time ruby -e 'require "./config/environment"'

results

# ruby 1.9.2p136 (2010-12-25 revision 30365) [x86_64-darwin10.6.0]
real	0m24.660s
user	0m21.236s
sys	0m2.234s

# ruby 1.9.3dev (2011-06-01) [x86_64-darwin10.7.0] with patch
real	0m21.619s
user	0m18.043s
sys	0m1.661s