rbenv-gem-rehash plugin 1.0.0

Closes Homebrew/homebrew#17329.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Formula/rbenv-gem-rehash.rb

@@ -0,0 +1,25 @@
+require 'formula'
+
+class RbenvGemRehash < Formula
+  homepage 'https://github.com/sstephenson/rbenv-gem-rehash'
+  url 'https://github.com/sstephenson/rbenv-gem-rehash/archive/v1.0.0.tar.gz'
+  sha1 '40962ef5cda77ff46c0d0a3f262076b58088dd57'
+
+  depends_on 'rbenv'
+
+  def install
+    prefix.install Dir['*']
+
+    ln_sf opt_prefix, "#{HOMEBREW_PREFIX}/var/lib/rbenv/plugins/#{name}"
+  end
+
+  def caveats; <<-EOS.undent
+    If the GEM_PATH environment variable is undefined, rbenv-gem-rehash must
+    first execute the gem env gempath command to retrieve RubyGems' default path
+    so that it can can append to the path rather than override it. This can take
+    a while--from a few hundred milliseconds on MRI to several seconds on
+    JRuby--so the default path for the current Ruby version is cached to the
+    filesystem the first time it is retrieved.
+    EOS
+  end
+end