不能设置语言环境，很好。我的 VPS 给了我一个残缺的 Ubuntu 16.04 发行版：
$ export LC_ALL="en_US.UTF-8"
-bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8)
$ locale -a
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_COLLATE to default locale: No such file or directory
C
C.UTF-8
POSIX
$ locale
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: …