PHP 7.1 Xdebug not installed.

[mshalmanov]

When in the env file set DOCKER_PHP_ENABLE_XDEBUG='on' and active php 7.1, docker not can install xdebug and show error

=> ERROR [5/9] RUN if [ "on" == "on" ]; then yes | pecl install xdebug && echo "zend_extension=$(find /usr/local/lib/php/extension 6.4s
ERROR: Service 'php-7.1' failed to build : Build failed