This PR enabled clouds on mac.
https://github.com/Unity-Technologies/Graphics/pull/4356

Before it nothing was rendering at all on mac, and now its almost good, but you can see a strange ring below the horizon (see video).

Reproduction:
1) Open any HDRP project
2) Checkout master or PR branch from above
3) Create new Outdoor scene
4) Enable Volumetric Clouds in the HDRP asset and Default Settings for camera
5) Add Volumetric clouds override and enable it with default settings
6) Increase Far plane to 1000 000 of the scene view camera

Expected result: clouds are visible without artefacts
Actual result: Only in scene view, there is a strange ring shape artefact