maintenance_nag()

function maintenance_nag() {
	include( ABSPATH . WPINC . '/version.php' ); // include an unmodified $wp_version
	global $upgrading;
	$nag = isset( $upgrading );
	if ( ! $nag ) {
		$failed = get_site_option( 'auto_core_update_failed' );
		/*
		 * If an update failed critically, we may have copied over version.php but not other files.
		 * In that case, if the installation claims we're running the version we attempted, nag.
		 * This is serious enough to err on the side of nagging.
		 *
		 * If we simply failed to update before we tried to copy any files, then assume things are
		 * OK if they are now running the latest.
		 *
		 * This flag is cleared whenever a successful update occurs using Core_Upgrader.
		 */
		$comparison = ! empty( $failed['critical'] ) ? '>=' : '>';

		if ( isset( $failed['attempted'] ) && version_compare( $failed['attempted'], $wp_version, $comparison ) ) {
			$nag = true;
		}
	}

	if ( ! $nag )
		return false;

	if ( current_user_can('update_core') )
		$msg = sprintf( __('An automated ClassicPress update has failed to complete - <a href="%s">please attempt the update again now</a>.'), 'update-core.php' );
	else
		$msg = __('An automated ClassicPress update has failed to complete! Please notify the site administrator.');

	echo "<div class='update-nag'>$msg</div>";
}