title: How do I change the ~/.bundler directory location?
body: <p>My home directory is a mounted NFS share and the local root doesn't have permissions to enter my user directory and it causes some errors when bundler removes the cached folders. (See sample output of 'bundle install' below).</p>
  
  <p>I'd like to move the ~/.bundler directory to local disk, if possible. I've been able to move my gems and rvm folders, but I can't for the life of me figure out where to change the bundler directory.</p>
  
  <p>Anyone know how to do this?</p>
  
  <pre><code>$ bundle install
  Checking out files: 100% (140/140), done.
  Checking out files: 100% (9/9), done.
  Fetching source index for http://rubygems.org/
  Enter your password to install the bundled RubyGems to your system: 
  mv: cannot remove `/auto/home2/borgnk/.bundler/tmp/9517/cache/rake-0.8.7.gem': Permission denied
  Using rake (0.8.7) 
  mv: cannot remove `/auto/home2/borgnk/.bundler/tmp/9517/cache/abstract-1.0.0.gem': Permission denied
  Using abstract (1.0.0) 
  mv: cannot remove `/auto/home2/borgnk/.bundler/tmp/9517/cache/activesupport-3.0.7.gem': Permission denied
  Using activesupport (3.0.7) 
  mv: cannot remove `/auto/home2/borgnk/.bundler/tmp/9517/cache/builder-2.1.2.gem': Permission denied
  Using builder (2.1.2) 
  mv: cannot remove `/auto/home2/borgnk/.bundler/tmp/9517/cache/i18n-0.5.0.gem': Permission denied
  Using i18n (0.5.0) 
  mv: cannot remove `/auto/home2/borgnk/.bundler/tmp/9517/cache/activemodel-3.0.7.gem': Permission denied
  Using activemodel (3.0.7) 
  mv: cannot remove `/auto/home2/borgnk/.bundler/tmp/9517/cache/erubis-2.6.6.gem': Permission denied
  Using erubis (2.6.6) 
  mv: cannot remove `/auto/home2/borgnk/.bundler/tmp/9517/cache/rack-1.2.2.gem': Permission denied
  Using rack (1.2.2) 
  mv: cannot remove `/auto/home2/borgnk/.bundler/tmp/9517/cache/rack-mount-0.6.14.gem': Permission denied
  ...
  </code></pre>