From eba682bcf5400bcfce4dc6e1d64d6029b2f05fc1 Mon Sep 17 00:00:00 2001
From: Terence Lee <hone02@gmail.com>
Date: Sun, 14 Oct 2012 14:40:29 -0700
Subject: [PATCH] store the buildpack version in the cache

---
 lib/language_pack/ruby.rb | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/lib/language_pack/ruby.rb b/lib/language_pack/ruby.rb
index c8d85cb67..75cc57e4e 100644
--- a/lib/language_pack/ruby.rb
+++ b/lib/language_pack/ruby.rb
@@ -5,6 +5,7 @@
 
 # base Ruby Language Pack. This is for any base ruby app.
 class LanguagePack::Ruby < LanguagePack::Base
+  BUILDPACK_VERSION   = "v40"
   LIBYAML_VERSION     = "0.1.4"
   LIBYAML_PATH        = "libyaml-#{LIBYAML_VERSION}"
   BUNDLER_VERSION     = "1.2.1"
@@ -577,10 +578,11 @@ def run_assets_precompile_rake_task
   def load_bundler_cache
     cache_load "vendor"
 
-    full_ruby_version  = run(%q(ruby -v)).chomp
-    heroku_metadata    = "vendor/heroku"
-    ruby_version_cache = "#{heroku_metadata}/ruby_version"
-    bundler_cache      = "vendor/bundle"
+    full_ruby_version       = run(%q(ruby -v)).chomp
+    heroku_metadata         = "vendor/heroku"
+    ruby_version_cache      = "#{heroku_metadata}/ruby_version"
+    buildpack_version_cache = "vendor/heroku/buildpack_version"
+    bundler_cache           = "vendor/bundle"
 
     # fix bug from v37 deploy
     if File.exists?("vendor/ruby_version")
@@ -604,6 +606,9 @@ def load_bundler_cache
     File.open(ruby_version_cache, 'w') do |file|
       file.puts full_ruby_version
     end
+    File.open(buildpack_version_cache, 'w') do |file|
+      file.puts BUILDPACK_VERSION
+    end
     cache_store heroku_metadata
   end
 end