I have tried to configure locale correctly before like How to fix set locale error? - Shammerism, but I was faced with the case that the way written in this article doesn't recover the locale. After editing /etc/environment, the following error still appears with perl -v.
perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = (unset), LC_ALL = "en", LC_CTYPE = "en_US.UTF-8", LANG = "C" are supported and installed on your system. perl: warning: Falling back to the standard locale ("C").
The result of locale -a in this environment is below.
# 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
Not installed en locale. This is a test environment so I don't want to add new locale. I should edit /etc/environment like below.
# cat /etc/environment LANG=C LC_ALL=C LC_CTYPE=C.UTF-8