try

announcement.gemspec

@@ -24,7 +24,7 @@ all_template.each do |folder|
           end
         end
       end
-    rescue
+    rescue => e
       puts "not found #{folder}assets/stylesheets/template/base/_variables.scss"
     end
   end
@@ -34,7 +34,7 @@ if old_gemfile_text != new_gemfile_text
     file.write new_gemfile_text
   end
   Thread.current = Thread.new do
-    Bundler.with_clean_env
+    Bundler.with_clean_env do
       system("bundle update")
     end
   end