Custom loop to display custom post_type in sidebar

I’m working off of a local server, so can ‘t provide a link. Using Genesis with NewsPro theme.
While successfully created a custom post_type, having trouble using a custom loop to display the posts in the sidebar. Am getting “Fatal error: Call to a member function the_post() on a non-object.”
Here’s my code, which works fine up to the while loop. (I tested the If loop, and it places echoed text in the sidebar with no errors.)
Have found a lot of posts on similar issues, but not this combo. Greatly appreciate some help. Thanks.

//* Create a newsbit widget area below other sidebar widgets with a custom loop that displays newsbit post types

//* Register a widget area called 'newsbit_widget'
genesis_register_sidebar( array(
 'id' => 'newsbit_widget',
 'name' => __( 'Newsbit widget area' ),
 'description' => __( 'This is where newsbits go' ),
) );

//* Hook newsbit_widget area after other sidebar widgets
function add_newsbit_widget() {
	$args = array( 'post_type' => 'newsbit', 'posts_per_page' => 10 );
	$custom_loop = new WP_Query( $args );
	if ( $custom_loop->have_posts() ) {
		while( $custom_loop->have_posts() ): $loop->the_post();
		echo 'this works';
		endwhile;
	}
	wp_reset_postdata();
}
add_action( 'genesis_after_sidebar_widget_area', 'add_newsbit_widget' );