ARGGGHHH - Silent failures!

I’ve just spent ages trying to find out why I couldn’t add some default views to drupal

I’d set up my views, exported them added them to a module in a hook_views_default_views() function…

and nothing happened.

First I though this was caching - but much cache clearing and debugging later…

I realised that if the view requires categories that don’t exist - it just gets silently dropped - no error - no warning it just doesn’t work!!!

This seems to be a general Drupal thing - all too often failures are silent - and very hard to track down.