From ef6a00f955da0359bdd63f31cec6699d74569cfc Mon Sep 17 00:00:00 2001
From: Andre Arko <andre@arko.net>
Date: Sun, 11 Apr 2010 20:45:55 -0700
Subject: [PATCH] Print better error during install when you need to relock

Closes #272
---
 lib/bundler.rb            | 1 +
 lib/bundler/cli.rb        | 6 +++++-
 lib/bundler/definition.rb | 2 +-
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/bundler.rb b/lib/bundler.rb
index dfda6481638..5b21968d1b2 100644
--- a/lib/bundler.rb
+++ b/lib/bundler.rb
@@ -38,6 +38,7 @@ class GemfileNotFound  < BundlerError; status_code(10) ; end
   class GemNotFound      < BundlerError; status_code(7)  ; end
   class VersionConflict  < BundlerError; status_code(6)  ; end
   class GemfileError     < BundlerError; status_code(4)  ; end
+  class GemfileChanged   < GemfileError; status_code(4)  ; end
   class PathError        < BundlerError; status_code(13) ; end
   class GitError         < BundlerError; status_code(11) ; end
   class DeprecatedMethod < BundlerError; status_code(12) ; end
diff --git a/lib/bundler/cli.rb b/lib/bundler/cli.rb
index 4f8259e49ff..0ef97049a54 100644
--- a/lib/bundler/cli.rb
+++ b/lib/bundler/cli.rb
@@ -85,7 +85,11 @@ def install(path = nil)
 
       remove_lockfiles if options[:relock]
 
-      Installer.install(Bundler.root, Bundler.definition, opts)
+      begin
+        Installer.install(Bundler.root, Bundler.definition, opts)
+      rescue GemfileChanged
+        raise GemfileChanged, "You changed your Gemfile after locking. Please run `bundle install --relock`."
+      end
 
       lock if options[:relock]
       cache if Bundler.root.join("vendor/cache").exist?
diff --git a/lib/bundler/definition.rb b/lib/bundler/definition.rb
index 91d0c58ddf3..d1b9a93b54f 100644
--- a/lib/bundler/definition.rb
+++ b/lib/bundler/definition.rb
@@ -17,7 +17,7 @@ def self.from_lock(lockfile)
 
       hash = Digest::SHA1.hexdigest(File.read("#{Bundler.root}/Gemfile"))
       unless locked_definition.hash == hash
-        raise GemfileError, "You changed your Gemfile after locking. Please relock using `bundle lock`"
+        raise GemfileChanged, "You changed your Gemfile after locking. Please relock using `bundle lock`"
       end
 
       locked_definition