Investigating a Perl locale warning over SSH

The following warning appeared intermittently on the server:

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

Resolving the locale mismatch

The warning identifies zh_TW.UTF-8 in LC_CTYPE and LANG. Perl falls back to the standard C locale because the requested settings are not supported or installed on this server. Check which locales are available with locale -a, then use an installed locale or ask the server administrator to install the requested one. The Perl locale documentation describes temporary and permanent remedies.