Adding a new step to a magento 2 checkout

Question

I'm attempting to add a new checkout step in my own custom theme. I've followed the instructions here:

http://devdocs.magento.com/guides/v2.2/howdoi/checkout/checkout_new_step.html

My theme extends another theme (Infortis Ultimo) but for some reason the new checkout step doesn't appear in my checkout. However when I activate the Ultimo theme, it shows (even though the step definition [checkout_index_index.xml, step.html, step-view.js] is in my module)

I'm guessing it's something to do with load order. But no matter what I try (sequences etc..) I can't get my module to load above any other module.

How do I get my theme to load in the correct order and override the necessary xml in order to render my step?

Answer 1

So it seems that having an

app/design/{module}/{package}/Magento_Checkout/layout/checkout_index_index.xml

will replace

app/code/{module}/{package}/view/frontend/layout/checkout_index_index.xml

I created the file in my app/design folder in an attempt to override something else. Magento will still parse both files and still complain if something is incorrect but offers no indication that it's completely ignoring the code version of the file.

Removed the app/design/.../.../Magento_Checkout/layout... and solved the problem.