LC_ALL = (unset)

Для решения ошибки вида

perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
    LANGUAGE = "en_US.UTF-8",
    LC_ALL = (unset),
    LANG = "en_US"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").

Необходимо добавить строчку в файле /etc/environment

LC_ALL=en_US.UTF-8
LANG=en_US.UTF-8