Improve deprecation message

1 files changed, 17 insertions, 7 deletions

diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb
index 399c22fb18..0dbc737de0 100644
--- a/activerecord/lib/active_record/attribute_methods.rb
+++ b/activerecord/lib/active_record/attribute_methods.rb
@@ -37,13 +37,23 @@ module ActiveRecord
       # accessors, mutators and query methods.
       def define_attribute_methods
         unless defined?(@attribute_methods_mutex)
-          ActiveSupport::Deprecation.warn(
-            "It looks like something (probably a gem/plugin) is removing or overriding the " \
-            "ActiveRecord::Base.inherited method. It is important that this hook executes so " \
-            "that your models are set up correctly. A workaround has been added to stop this " \
-            "causing an error in 3.2, but future versions will simply not work if the hook is " \
-            "overridden."
-          )
+          msg = "It looks like something (probably a gem/plugin) is overriding the " \
+                "ActiveRecord::Base.inherited method. It is important that this hook executes so " \
+                "that your models are set up correctly. A workaround has been added to stop this " \
+                "causing an error in 3.2, but future versions will simply not work if the hook is " \
+                "overridden. If you are using Kaminari, please upgrade as it is known to have had " \
+                "this problem.\n\n"
+          msg << "The following may help track down the problem:"
+
+          meth = method(:inherited)
+          if meth.respond_to?(:source_location)
+            msg << " #{meth.source_location.inspect}"
+          else
+            msg << " #{meth.inspect}"
+          end
+          msg << "\n\n"
+
+          ActiveSupport::Deprecation.warn(msg)
 
           @attribute_methods_mutex = Mutex.new
         end