Addenda: I meant #816865, not 816815
Upgrading bluez locally gets rid of the prior errors, but produces other errors, and the mouse still doesn't work (at first, but keep reading) I cleared the previous pairing and tried to re-pair, just to be "safe" Mar 30 21:20:56 hostname bluetoothd[1421]: GATT service objects disabled Mar 30 21:20:56 hostname kernel: [ 36.700194] Bluetooth: SMP security requested but not available The last line repeats every ~15 *milliseconds* until it times out and gives up. That sounds like https://bugzilla.kernel.org/show_bug.cgi?id=104011 Following the suggestion there (bluetoothctl power off / power on) I was able to pair and use the mouse! The kernel.org ticket suggests it will be temporarily broken again when I reboot, and that the root cause of that is a udev rule causing the bluetooth host to be brought up in "legacy mode".
