Environment note for anyone wiring OpenXR test content into an auto-launch path.
Khronos hello_xr prints "Press any key to shutdown..." and polls stdin. Launched from systemd (or any context where stdin is /dev/null or closed), the poll sees EOF immediately and the application exits. In WiVRn this presents as the headset sitting on "waiting for application" while the server log shows the application was launched successfully.
Workaround, now used in the msi1060 WiVRn config and documented in the hydrahelloxr runbook:
"application": ["/bin/sh", "-c", "sleep infinity | exec /opt/experiencenet/hellohydra_xr/hellohydra_xr -g Vulkan"]
The pipe gives stdin a source that never delivers data and never reaches EOF.