CubebDeviceEnumerator relies on notification callbacks to update it's stored device list. The notification logic in not implemented in cubeb remote. The register method returns success though. If it returned an error then enumerator could work around the case and enumerate every time. The method is expected to be implemented soon. Till then I made a small patch to return an error. This will restore the enumerate devices functionality until we get the permanent solution. I'll add the patch directly to gecko. Feel free to r- of you want me to go through the whole import process. [1] https://searchfox.org/mozilla-central/rev/c56977420df7a1b692ce0f7e499ddb364d9fd7b2/media/audioipc/client/src/context.rs#273

See also https://github.com/djg/audioipc-2/issues/50