Againt, the directory is a Pathname object now

rubberin

@@ -191,7 +191,7 @@ notifier = INotify::Notifier.new
 dirs = files.map { |file| Pathname.new(file).dirname.realpath }.uniq
 dirs.each do |dir|
   # Set up a watch per directory
-  notifier.watch(dir, :close_write) do |ev|
+  notifier.watch(dir.to_s, :close_write) do |ev|
     # Only compile if a dependency of the input file has been modified
     file_path = (dir + ev.name).to_s
     next unless files.include? file_path