[BUG] Graphical artifacts in SteamVR/games

[bradgy]

Describe the bug I have been experiencing a line of light/dots coming in an upwards z direction off (usually) bright/white objects. First noticed after an update to mesa while using EndeavourOS and playing Half Life Alyx, now I see it with a fresh install of Ubuntu 20.04 LTS (Beta) in other games and in SteamVR Home.

To Reproduce Steps to reproduce the behavior:

1. Install either EndeavourOS, or Ubuntu 20.04 LTS (beta)
2. Install steam from the repos. Install SteamVR. Opt into both betas.
3. Attach Index headset and knuckles controllers and update if needed
4. Play a game, notice graphical artifacts that look like below:

Expected behavior To see clean objects without bright lines emanating from them

System Information (please complete the following information):

• Distribution: Ubuntu 20.04 LTS (beta)
• SteamVR version: 1.11.11
• Steam client version: Apr 16 2020 at 23:16
• Opted into Steam client beta?: Yes
• Graphics driver version: Mesa 20.0.4 (LLVM 9.0.1) (errors related to libvulkan i386 elfclass32)
• Gist for SteamVR System Information: https://gist.github.com/bradgy/11d757c685f2f33cda0000b7e923b9b5

Screenshots

SteamVR Home view through eyepiece (taken with phone camera to illustrate problem, if there's a better way to capture eye output, please let me know)

Same field of view on HDMI monitor

Beat Saber view through eyepiece

Same field of view on HDMI monitor

Additional context I don't think this is a hardware issue, because the behaviour seems confined to specific objects in games/the environment. It doesn't appear at all in the "staging area" (not sure of exact name, the one with the purple vista, "Next Up" pop ups etc), for instance. Happy to provide any further details and do further tests if needed. Thanks in advance.

Note: Commenters who are also experiencing this issue are encouraged to include the "System Information" section in their replies.

[bradgy]

Update to this, these artifacts have not gone away over time, and were still present in the eyepiece fields of view after I got around to testing with a Windows 7 rig.

I'm therefore leaning towards it being a hardware issue, and have submitted a support ticket to Steam to see what they suggest.

Given no one else has mentioned a similar problem in this thread, I'm closing the issue for the time being so as not to clog the bug tracker.