Canonical's Mir Patches Are Breaking RADV With Stock Mesa On Ubuntu
If you have been trying to use the RADV Radeon Vulkan driver that's packaged for Ubuntu but find it not working, chances are it's caused by Canonical's patches for Mir support.
RADV developer David Airlie of Red Hat today sent out a notice that Canonical's Mir patches in their Mesa packages are breaking the RADV driver. Ubuntu isn't shipping Vulkan drivers by default yet but ANV and RADV can be easily obtained on Ubuntu Linux systems via sudo apt install mesa-vulkan-drivers for the RADV/ANV drivers built against their stock version of Mesa.
It turns out that those stock Mesa packages that are still bundling Mir support by default actually end up breaking RADV support than allowing it to work. Users have been incorrectly attributing RADV being broken when in fact it's the Ubuntu packaging of the driver due to these Mir patches, Airlie warned.
Hopefully it will end up being fixed in short order. Though if wanting to try the Mesa Vulkan drivers on Ubuntu, I'd highly encourage you to use the Padoka PPA instead given the rapid rate of change/progress for the Mesa OpenGL and Vulkan drivers. Generally speaking it should be as easy as sudo apt-add-repository ppa:paulo-miguel-dias/mesa && sudo apt update && sudo apt dist-upgrade. (Do note though based on personal experience if you have mesa-vulkan-drivers already installed and try to enable Padoka PPA without first removing mesa-vulkan-drivers, APT will generally throw a fit.)