升級到 ruby 2.1 遇到 could not find a temporary directory

如果在升級 ruby 到 2.1 之後撞到這種錯誤訊息：

/usr/local/lib/ruby/2.1/tmpdir.rb:34:in `tmpdir': could not find a temporary directory (ArgumentError)

就把 /tmp 的 Sticky bit 加上去吧

chmod +t /tmp

最近怎麼老是被 server 咬呢 :~~