Source

File: wp-includes/class-wp-fatal-error-handler.php

protected function display_default_error_template( $error, $handled ) {
		if ( ! function_exists( '__' ) ) {
			wp_load_translations_early();
		}

		if ( ! function_exists( 'wp_die' ) ) {
			require_once ABSPATH . WPINC . '/functions.php';
		}

		if ( ! class_exists( 'WP_Error' ) ) {
			require_once ABSPATH . WPINC . '/class-wp-error.php';
		}

		if ( true === $handled && wp_is_recovery_mode() ) {
			$message = __( 'There has been a critical error on your website, putting it in recovery mode. Please check the Themes and Plugins screens for more details. If you just installed or updated a theme or plugin, check the relevant page for that first.' );
		} elseif ( is_protected_endpoint() ) {
			$message = __( 'There has been a critical error on your website. Please check your site admin email inbox for instructions.' );
		} else {
			$message = __( 'There has been a critical error on your website.' );
		}

		$message = sprintf(
			'<p>%s</p><p><a href="%s">%s</a></p>',
			$message,
			/* translators: Documentation explaining debugging in WordPress. */
			__( 'https://wordpress.org/support/article/debugging-in-wordpress/' ),
			__( 'Learn more about debugging in WordPress.' )
		);

		$args = array(
			'response' => 500,
			'exit'     => false,
		);

		/**
		 * Filters the message that the default PHP error template displays.
		 *
		 * @since 5.2.0
		 *
		 * @param string $message HTML error message to display.
		 * @param array  $error   Error information retrieved from `error_get_last()`.
		 */
		$message = apply_filters( 'wp_php_error_message', $message, $error );

		/**
		 * Filters the arguments passed to {@see wp_die()} for the default PHP error template.
		 *
		 * @since 5.2.0
		 *
		 * @param array $args Associative array of arguments passed to `wp_die()`. By default these contain a
		 *                    'response' key, and optionally 'link_url' and 'link_text' keys.
		 * @param array $error Error information retrieved from `error_get_last()`.
		 */
		$args = apply_filters( 'wp_php_error_args', $args, $error );

		$wp_error = new WP_Error(
			'internal_server_error',
			$message,
			array(
				'error' => $error,
			)
		);

		wp_die( $wp_error, '', $args );
	}