Custom PHP error handling for displaying fatal errors when they happen with a greater level of detail than normally shown for a site. Place this file at: wp-content/php-error.php

php-error.php

<?php
/**
 * Custom PHP error handling for displaying fatal errors when they happen with a greater level of detail than normally
 * shown for a site.
 *
 * Place this file at: wp-content/php-error.php
 *
 * By default, it will fallback to the normal WP behavior for error pages/display.
 *
 * If using WP-CLI or setting `skcdebug=1` in the request (GET/POST/etc), then it will display the full error details.
 *
 * @var WP_Fatal_Error_Handler $this    The fatal error handler instance that this file is loaded into the context for.
 * @var array                  $error   Error information retrieved from `error_get_last()`.
 * @var true|WP_Error          $handled Whether Recovery Mode handled the fatal error.
 */

if ( ! defined( 'WP_CLI' ) && empty( $_REQUEST['skcdebug'] ) ) {
	// Public requests will not display the PHP error details.
	$this->display_default_error_template( $error, $handled );
} else {
	echo '<h1>Site PHP Error</h1>';

	var_dump( $error['type'] );

	echo '<pre>';
	echo $error['message'] . "\n";

	var_dump( $error['file'] );
	var_dump( $error['line'] );
	var_dump( $handled );
	var_dump( debug_backtrace( DEBUG_BACKTRACE_IGNORE_ARGS ) );
	echo '</pre>';
}