Detected system locale encoding (ANSI_X3.4-1968, locale "") is not UTF-8

Detected system locale encoding (ANSI_X3.4-1968, locale "") is not UTF-8.
Qt shall use a UTF-8 locale ("C.UTF-8") instead. If this causes problems,
reconfigure your locale. See the locale(1) manual for more information.

$ locale
LANG=C.UTF-8
LC_CTYPE="C.UTF-8"
LC_NUMERIC="C.UTF-8"
LC_TIME="C.UTF-8"
LC_COLLATE="C.UTF-8"
LC_MONETARY="C.UTF-8"
LC_MESSAGES="C.UTF-8"
LC_PAPER="C.UTF-8"
LC_NAME="C.UTF-8"
LC_ADDRESS="C.UTF-8"
LC_TELEPHONE="C.UTF-8"
LC_MEASUREMENT="C.UTF-8"
LC_IDENTIFICATION="C.UTF-8"
LC_ALL=