The Ruby source trees were initially checked in pristine such that a patch
against the source tree can be easily generated with subversion.  Use the
following key:

Ruby 1.8.5  rev 1
Ruby 1.8.6  rev 68


To generate a patch against 1.8.5, for example, run:

svn diff -r1:HEAD http://svn.joyent.com/ruby-dtrace/ruby-1.8.5