UTF-8 encoding issue fix was dropped for some reason. Here it is again.

vendor/chance/lib/chance.rb

@@ -16,12 +16,12 @@ class << self
     def add_file(path, content=nil)
       mtime = 0
       if content.nil?
-        mtime = File.new(path).mtime
+        mtime = File.mtime(path).to_f
       end
 
       if @files[path]
-        mtime = File.new(path).mtime
-        update_file(path) if mtime > @files[path][:mtime]
+        mtime = File.mtime(path).to_f
+        update_file(path, content) if mtime > @files[path][:mtime]
         return
       end
 
@@ -44,7 +44,7 @@ def update_file(path, content=nil)
 
       mtime = 0
       if content.nil?
-        mtime = File.new(path).mtime
+        mtime = File.mtime(path).to_f
       end
 
       file = {
@@ -87,7 +87,8 @@ def get_file(path)
       file = @files[path]
 
       if file[:content].nil?
-        f = File.open(path, "rb")
+        # note: CSS files should be opened as UTF-8.
+        f = File.open(path, path =~ /css$/ ? 'r:UTF-8' : 'rb')
         file[:content] = f.read
         f.close
       end