Ubuntu Server 12.04 で次のような警告が出てパッケージのインストールがうまく行かない場合があります。 perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = "en_US:en", LC_ALL = (unset), LC_CTYPE = "ja_JP.UTF-8", LC_COLLATE = "ja_JP.UTF-8", LC_MESSAGES = "ja_JP.UTF-8", LANG = "en_US.UTF-8" are supported and installed on your system. perl: warning: Falling back to the standard locale ("C").