require 'thread' for Mutex dependency

jeremy · jeremy · commit 6f17422ca7ce · 2010-08-31T16:38:52.000-07:00
diff --git a/activesupport/lib/active_support/dependencies.rb b/activesupport/lib/active_support/dependencies.rb
@@ -1,3 +1,5 @@
+require 'thread'
+
 module ActiveSupport #:nodoc:
   module Dependencies #:nodoc:
     extend self
