Make explicit warnings when an asset is not found

Author: arlm

lib/requirejs/rails/builder.rb

@@ -16,7 +16,11 @@ def build
     end
 
     def digest_for(path)
-      Rails.application.assets.file_digest(path).hexdigest
+      if !Rails.application.assets.file_digest(path).nil?
+        Rails.application.assets.file_digest(path).hexdigest
+      else
+        puts "Asset digest not found:", path
+      end
     end
 
     def generate_rjs_driver
@@ -26,4 +30,4 @@ def generate_rjs_driver
       end
     end
   end
-end
+end