Given the current issue with dxvk building on macOS (#497) this would likely be very helpful.
That PR is in fact a prerequisite for work on making Proton's build system more robust. I should have some PRs to that effect this week.
Speaking of building dxvk, there already is a docker image available for that specifically: https://github.com/cheald/dxvk-docker/
#793 Adds support for builds that use the ValveSoftware/steam-runtime#91 docker images and are greatly reduced in setup requirements. dxvk/mingw-w64 remains as a host-setup pain point.
Proton now uses docker for building by default
The build process for linux is pretty bad, in my opinion. I would propose implementation of docker as a way of making the build pipeline easier and more robust.
There is a pull request open for the steam runtime I've reached out to, so we can get that integrated. If I don't hear back I'll start cracking away locally and seeing where it is messing up, and making another PR.
If done right, docker can unify build/devel process for windows, mac, and linux.
https://github.com/ValveSoftware/steam-runtime/pull/91