title: How to downgrade Perl on Mac OS X Mavericks
body: <p>The newly release Mavericks has removed the deprecated module "Switch.pm" from its repository. 
  However, I have recently try to build AOSP source tree and it somehow uses this module to generate "make-hash-tools.pl"</p>
  
  <p>The Mavericks has perl version of 5.16.2, and its predecessor Mountain Lion has a 5.12.4. Is there a way to downgrade my Perl?</p>
  
  <p>Compilation error looks like this:</p>
  
  <pre><code>  Can't locate Switch.pm in @INC (@INC contains: /Library/Perl/5.16/darwin-thread-\ 
    multi-2level /Library/Perl/5.16 /Network/Library/Perl/5.16/darwin-thread-multi-2level\
    /Network/Library/Perl/5.16 /Library/Perl/Updates/5.16.2\
    /System/Library/Perl/5.16/darwin-thread-multi-2level /System/Library/Perl/5.16\
    /System/Library/Perl/Extras/5.16/darwin-thread-multi-2level \
    /System/Library/Perl/Extras/5.16 .) at external/webkit/Source/WebCore\
    /make-hash-tools.pl line 23.
  </code></pre>
  
  <p>Thanks~!</p>