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

To fix, add this to /etc/environment, then logout & login:

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