Why environment variables don’t suppress WP-CLI PHP Deprecated warnings — the phar + shebang path and a three-part structural fix

A previous post covered how to absorb PHP 8.2 Deprecated warnings from WP-CLI using a three-layer defense . The approach — prepending WP_CLI_PHP_ARGS to set error_reporting — works in many environments. But a case came up where Deprecated warnings wouldn’t disappear despite the same configuration. Tracing the cause revealed a structural reason why the environment variable never arrived. This post records that root cause and the three-part fix added in v1.6.8. Why environment variables don’t arrive — the phar + shebang execution path An agency reported that on Xserver, plugin list retrieval was failing across multiple sites (referred to here as "site A / site B") with a large volume of Deprecated messages. We reproduced the same behavior on our own Xserver setup (PHP 8.2.30, WP-CLI 2.7.1) and traced the execution path. Xserver’s /usr/bin/wp is a phar binary. Inside, it starts with a #!/usr/bin/env php shebang, so the actual startup sequence looks like this: shell → /usr/bin/wp (shebang: #!/usr/bin/env php) ↓ env locates php and starts it ↓ php loads the phar → WP-CLI runs In this path, WP_CLI_PHP_ARGS is never read as a PHP startup option. WP_CLI_PHP_ARGS is supposed to let WP-CLI pass a -d flag to PHP, but when PHP itself is launched via shebang, control never reaches the point where WP-CLI can inject that flag into PHP’s invocation. # doesn’t work — /usr/bin/wp on Xserver is a shebang-launched phar WP_CLI_PHP_ARGS = "-d error_reporting='E_ALL & ~E_DEPRECATED'" wp plugin list --format = json # works — -d goes directly to the php binary php -d error_reporting = 'E_ALL & ~E_DEPRECATED & ~E_USER_DEPRECATED' /tmp/wp-cli-2.7.1.phar plugin list --format = json We verified this against our production setup: with the first form, 407 Deprecated lines remained; with the second, 0. Pillar A — detecting the php-direct path and injecting -d The fix: inspect wp_cli_path for whether it’s a php-direct invocation, and if so, inject -d error_reporting immediately after the PHP