Current DevCentral environment variables for php-fpm:
$ cat /usr/local/etc/envvars declare -x HOME="/root" declare -x HOSTNAME="51099144b9cd" declare -x MYSQL_ENV_MYSQL_MAJOR="5.7" [... other MYSQL_ variables ...] declare -x OLDPWD declare -x PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin" declare -x PHABRICATOR_ALT_FILE_DOMAIN="http://phabricator-files-for-devcentral-nasqueron.spacetechnology.net" [... other PHABRICATOR_ variables ...] declare -x PHP_BUILD_DEPS="bzip2 file libbz2-dev libcurl4-openssl-dev libjpeg-dev libmcrypt-dev libpng12-dev libreadline6-dev libssl-dev libxml2-dev" [... other PHP_ variables ...] declare -x PWD="/opt/phabricator" declare -x SHLVL="1" declare -x TERM="xterm"
That should contain LC_ variables set to an UTF-8 locale.