Mpris does not work: Unhandled DBus message

[busti]

Description I am trying to setup mpris support on a RasPi 4 running nixos, however I have no success in doing so. Playback is working fine and the process does not crash, but there are some error messages hinting at a DBus problem:

Jan 23 03:52:41 bemmer dbus-launch[42171]: Unhandled DBus message: (Signal, Some("/org/freedesktop/DBus"), Some("org.freedesktop.DBus"), Some("NameAcquired"))
Jan 23 03:52:41 bemmer dbus-launch[42171]: Unhandled DBus message: (Signal, Some("/org/freedesktop/DBus"), Some("org.freedesktop.DBus"), Some("NameAcquired"))

Lots of these steps are probably unnecessary. I just wanted to give a full description of what I am trying to do.

I believe the problem lies with spotifyd failing to connect to DBus correctly, however it does connect to it, because running it outside of dbus-launch fails with a different error message.

However, I have no idea how to debug this. I have thrown about 4 hours at the different solutions provided in #271 , #434 and #668
The service does not show up in any dbus-send output.
How can I debug this further?

To Reproduce

1. Install NixOs on a rasperry pi 4
2. Overlay the spotifyd package to compile with mpris support:

   nixpkgs.overlays = [(self: super: {
   spotifyd = super.spotifyd.override (old: {
     withMpris = true;
   });
   })];

3. Enable the spotifyd service using the following config:

   services.spotifyd = {
   enable = true;
   settings.global = {
     bitrate = 320;
     zeroconf_port = 18572;
     initial_volume = "30";
     device_type = "computer";
     use_mpris = true;
   };
   };

4. Override the service config to run the spotifyd service inside dbus-launch with the same user as the desktop env:

   systemd.services.spotifyd.serviceConfig = {
   DynamicUser = lib.mkForce false;
   User = "c3h";
   ExecStart = lib.mkForce "${pkgs.dbus}/bin/dbus-launch ${pkgs.spotifyd}/bin/spotifyd --no-daemon --config-path ${ (pkgs.formats.toml {}).generate "spotify.conf" config.services.spotifyd.settings }";
   };

5. Allow the necessary ports through the firewall:

   networking.firewall.allowedTCPPorts = [ 4070 config.services.spotifyd.settings.global.zeroconf_port ];
   networking.firewall.allowedUDPPorts = [ 5353 ];

Full config can be found here (does not contain mpris feature overlay):
https://git.neulandlabor.de/Yuka/c3h-nixfiles

Expected behavior spotifyd connects to DBus allowing it to be controlled via mpris, i.e. using playerctl

Logs

Click to show logs

https://gist.github.com/busti/62b65728143f1f83ffe765c2c0f0b8d4 ``` Jan 23 04:38:37 bemmer dbus-launch[45708]: shut down IO Jan 23 04:38:37 bemmer dbus-launch[45708]: deregistering handle with poller Jan 23 04:38:37 bemmer dbus-launch[45708]: dropping I/O source: 6 Jan 23 04:38:37 bemmer dbus-launch[45708]: loop poll - 52.435342ms Jan 23 04:38:37 bemmer dbus-launch[45708]: loop time - Instant { tv_sec: 108257, tv_nsec: 995358833 } Jan 23 04:38:37 bemmer dbus-launch[45708]: loop process, 15.333µs Jan 23 04:38:56 bemmer systemd[1]: Stopping spotifyd, a Spotify playing daemon... Jan 23 04:38:56 bemmer systemd[1]: spotifyd.service: Deactivated successfully. Jan 23 04:38:56 bemmer systemd[1]: Stopped spotifyd, a Spotify playing daemon. Jan 23 04:38:56 bemmer systemd[1]: spotifyd.service: Consumed 1.262s CPU time, received 9.0M IP traffic, sent 244.0K IP traffic. Jan 23 04:38:58 bemmer systemd[1]: Started spotifyd, a Spotify playing daemon. Jan 23 04:38:58 bemmer dbus-launch[46512]: Loading config from "/nix/store/wk5dxnsg8lnyiblbgz0mp0pzd8c9rym3-spotify.conf" Jan 23 04:38:58 bemmer dbus-launch[46512]: No username specified. Checking username_cmd Jan 23 04:38:58 bemmer dbus-launch[46512]: No username_cmd specified Jan 23 04:38:58 bemmer dbus-launch[46512]: No password specified. Checking password_cmd Jan 23 04:38:58 bemmer dbus-launch[46512]: No password_cmd specified Jan 23 04:38:58 bemmer dbus-launch[46512]: No proxy specified Jan 23 04:38:58 bemmer dbus-launch[46512]: Using software volume controller. Jan 23 04:39:08 bemmer dbus-launch[46512]: Connecting to AP "ap-gew1.spotify.com:443" Jan 23 04:39:08 bemmer dbus-launch[46512]: Authenticated as "6ug8p3g1e02rq9ywxuvyjpnnh" ! Jan 23 04:39:08 bemmer dbus-launch[46512]: Using alsa sink Jan 23 04:39:08 bemmer dbus-launch[46512]: Country: "DE" Jan 23 04:39:08 bemmer dbus-launch[46512]: Unhandled DBus message: (Signal, Some("/org/freedesktop/DBus"), Some("org.freedesktop.DBus"), Some("NameAcquired")) Jan 23 04:39:08 bemmer dbus-launch[46512]: Unhandled DBus message: (Signal, Some("/org/freedesktop/DBus"), Some("org.freedesktop.DBus"), Some("NameAcquired")) Jan 23 04:39:08 bemmer dbus-launch[46512]: Loading with Spotify URI Jan 23 04:39:09 bemmer dbus-launch[46512]: (211933 ms) loaded Jan 23 04:39:14 bemmer dbus-launch[46512]: Loading with Spotify URI Jan 23 04:39:14 bemmer dbus-launch[46512]: (233626 ms) loaded ```

Compilation flags

• [x] dbus_mpris
• [ ] dbus_keyring
• [x] alsa_backend
• [ ] portaudio_backend
• [ ] pulseaudio_backend
• [ ] rodio_backend

Versions (please complete the following information):

• OS: nixos-unstable; aarch64; 22.05pre-git (Quokka); rev: 581d2d6c9cd5c289002203581d8aa0861963a933
• Spotifyd: 0.3.2
• cargo: 1.57.0

[eladyn]

Hi and thanks for the detailed report!

The Unhandled DBus message: ... NameAcquired are quite normal as they only tell us that spotifyd received signals that it does not care about (in this case that services appeared on the bus).

I think that the real problem is the dbus-launch thing. I have never used that before, but as far as I understand (source), it creates a new session bus for this project, which you could connect to and does not use the existing session. So I assume that, when you use dbus-send from your normal environment, it uses a different session bus and not the one that was specifically created for spotifyd.

Thus, you should try to start spotifyd from within your session (e.g. through systemctl --user) or somehow provide it with the $DBUS_SESSION_BUS_ADDRESS environment variable to be able to reach it with dbus-send.

Hope this helps you get further!

[aniketfuryrocks]

Mpris issue with gnome40/41/42 and playerctld as well. Only the first song is updated. After that mpris controller is UN-responsive. The buttons do work, but state is not updated. .

[eladyn]

@aniketfuryrocks That is probably not related to this issue, but rather the missing implementation of the org.freedesktop.DBus.Properties.PropertiesChanged signal. There is #1025 that aims to fix that.

[busti]

Sorry for not replying immediately btw. I am having finals right now, I will get back to this once they are over.

[slondr]

@aniketfuryrocks That is probably not related to this issue, but rather the missing implementation of the org.freedesktop.DBus.Properties.PropertiesChanged signal. There is #1025 that aims to fix that.

1025 is merged now, so hopefully that's cleared up.