Custom RSS for taxonomy term

Going on the assumption I can use an RSS template as if it were a post loop, how come this returns a php error of “cannot use object of type WP_Query as array in”?

        $args = array('tax_query' => array(
		 'taxonomy' => 'show',
						'terms'    => 'the-anti-broadcast',)
	);
$posts = new WP_Query( $args );

        while(have_posts($posts)) : the_post($posts); ?>

The tax_query argument requires nested arrays. Since you did not do that, the code interpreter is picking up the next WP_Query line instead. Please review the examples for tax_query on the WP_Query docs page.

Yes, the RSS template is a specific kind of archive template that generates compatible XML. As long the XML is correct you can modify the template. However, adding a custom query to drive the main loop is sub-optimal. Instead use the “pre_get_posts” action to modify the RSS query. Verify the passed object is the main query and that it’s a feed request before modifying anything.

I don’t see why this is necessary. Why wouldn’t you use the term feed request?
https://example.com/show/the-anti-broadcast/feed/

You’re probably right now that I look at the situation. I just wanted to avoid injecting the extra iTunes (etc) tags and custom field into ALL my feeds through the functions file.
I’ll spend some time learning to use pre_get_posts and will share my results here for anyone who’ll search like I did in the future.

Thanks

This is a proper array to call a post type, taxonomy, and term into a wp_query in an RSS file

$args = array(
  'post_type' => 'shows' ,
  'orderby' => 'date' ,
  'order' => 'DESC' ,
  'posts_per_page' => -1,
    'tax_query'      => array(
            array(
                'taxonomy'  => 'show',
                 'field'     => 'tag_ID',
                  'terms'     => '3'
            )
        )
); 
$q = new WP_Query($args);
        while($q->have_posts()) : $q->the_post(); ?>