On SEPTEMBER 28, Valve told its own SteamVR-for-Linux tracker that the problem is “the NVIDIA 580 series driver INCOMPATIBILITY” — and that fragmenting the thread by GPU model is pointless when the DRIVER branch is the common FACTOR.

Mixed News, writing SEPTEMBER 30, ties that reply to seven owner reports since SEPTEMBER 7: Steam Link connects, the headset is identified, then vkCreateDevice returns -7 (VK_ERROR_EXTENSION_NOT_PRESENT), the COMPOSITOR never starts, and SteamVR shows ERROR 405 — “You may need to update your computer’s graphics driver.”
What Fails — and What Does Not
The failure is ABRUPT and early. Owners never reach a video-encode queue family log line; device CREATION dies FIRST. Cards in the thread range from a GTX 1080 Ti to an RTX 5090. Headsets include Quest 2, Quest 3, Quest 3S, and at least one Steam FRAME on Fedora 43 using the wireless ADAPTER.

An early AV1 theory did not hold: an RTX 4060 owner posted the same -7, undercutting the idea that only pre-Ada NVENC was to blame. Owner debugging with Vulkan loader TRACE later named the missing piece: VK_KHR_maintenance9. On 580.159.03, one report says the driver exposes maintenance1 through maintenance8 — one version short of what SteamVR asks for.

Workarounds Exist — Unless You Are on Pascal
Two owners describe exits that worked on their machines: move to Nvidia 595.91.07 and drop SteamVR to the previous 2.16.7 BRANCH, or rebase onto newer open kernel modules (one cited 615.71.09 on Bazzite) so VR STREAMING starts. Valve has CONFIRMED the 580-branch cause; it has not published a support article, known-issues note, or FIX timeline. The report stays open and unassigned.

Pascal owners say they are STUCK. The last branch that still supports GTX 10-series cards is 580, and that is exactly the branch Valve labeled INCOMPATIBLE. For metaverse and PC-VR streaming readers, the practical TAKEAWAY is narrow but sharp: if Linux Steam Link VR dies at device create with -7 on a 580 DRIVER, treat the driver series as the primary SUSPECT — distinct from today’s separate SteamOS 0.4.2 Steam Frame protocol notes.
Primary sources: Valve’s kisak-valve comment on GitHub issue #941 (SEPTEMBER 28) and the Mixed News summary (SEPTEMBER 30). Owner diagnoses of the missing Vulkan EXTENSION are reported as owner findings that FIT the thread, not as a Valve engineering write-up.