As soon as I add a call to drupal_add_feed in my theme template.php file I get this warning:
Warning: call_user_func_array() expects parameter 1 to be a valid callback, no array or string given in theme_get_registry() (line 277 of /var/www/example.com/includes/theme.inc).
The feed (created by Views) is valid, and the code works, i.e. it does add the meta tag. But the warning is unacceptable, obviously.
Fix? Something I'm doing wrong?