bluetoothd suddenly stopped working. The journalctl logs:

Jan 07 13:06:56 zira bluetoothd[1004]: src/profile.c:record_cb() Unable to get Hands-Free Voice gateway SDP record: Host is down
Jan 07 13:07:49 zira bluetoothd[1004]: Disconnected from D-Bus. Exiting.
Jan 07 13:07:49 zira bluetoothd[1004]: Endpoint unregistered: sender=:1.48 path=/MediaEndpoint/A2DPSink/sbc
Jan 07 13:07:49 zira bluetoothd[1004]: Endpoint unregistered: sender=:1.48 path=/MediaEndpoint/A2DPSink/sbc_xq_453
Jan 07 13:07:49 zira bluetoothd[1004]: Endpoint unregistered: sender=:1.48 path=/MediaEndpoint/A2DPSource/sbc_xq_453
Jan 07 13:07:49 zira bluetoothd[1004]: Endpoint unregistered: sender=:1.48 path=/MediaEndpoint/A2DPSink/sbc_xq_512
Jan 07 13:07:49 zira bluetoothd[1004]: Endpoint unregistered: sender=:1.48 path=/MediaEndpoint/A2DPSource/sbc_xq_512
Jan 07 13:07:49 zira bluetoothd[1004]: Endpoint unregistered: sender=:1.48 path=/MediaEndpoint/A2DPSink/sbc_xq_552
Jan 07 13:07:49 zira bluetoothd[1004]: Endpoint unregistered: sender=:1.48 path=/MediaEndpoint/A2DPSource/sbc_xq_552
Jan 07 13:07:49 zira bluetoothd[1004]: Endpoint unregistered: sender=:1.48 path=/MediaEndpoint/A2DPSource/sbc
Jan 07 13:07:49 zira acpid[740]: input device has been disconnected, fd 23
Jan 07 13:07:50 zira bluetoothd[1004]: dbus[1004]: arguments to dbus_message_new_method_call() were incorrect, assertion "destination == NULL || _dbus_check_is_valid_bus_name (destination)" failed in file ../../../dbus/dbus-message.c line 1364.
Jan 07 13:07:50 zira bluetoothd[1004]: This is normally a bug in some application using the D-Bus library.
Jan 07 13:07:50 zira bluetoothd[1004]:   D-Bus not built with -rdynamic so unable to print a backtrace
Jan 07 13:07:50 zira systemd[1]: bluetooth.service: Main process exited, code=killed, status=6/ABRT
Jan 07 13:07:50 zira systemd[1]: bluetooth.service: Failed with result 'signal'.

I have 2 bluetooth devices: speakers that are permanently connected,
and headphones, which normally get connected when I switch them on.
During a test, I noticed that the headphones were not connected to
my laptop, but only to my phone. I eventually disabled the bluetooth
on my phone, and it seems that this was at this time that bluetoothd
crashed, but I'm not sure (I don't see what else could trigger the
crash). I suppose that at this time, the headphones tried to connect
to the laptop.