Spotify D-Bus issue - cannot send CLI commands

[resill]

Please find below my detailed information regarding my problem, my desired result, and how to reproduce.

Plan

Premium

Country

The Netherlands

Device

➜  ~ neofetch --stdout
larry@gentoo 
--------------- 
OS: Gentoo/Linux x86_64 
Kernel: 4.17.5-zen 
Uptime: 1 hour, 36 mins 
Packages: 1002 
Shell: zsh 5.5.1 
Resolution: 1920x1080 
WM: i3 
Theme: Adwaita [GTK2] 
Icons: Adwaita [GTK2] 
Terminal: urxvtd 
Terminal Font: DejaVu Sans Mono 
CPU: Intel i5-2500K (4) @ 3.301GHz 
GPU: NVIDIA GeForce GTX 670 
GPU: Intel 2nd Generation Core Processor Family 
Memory: 1523MiB / 15947MiB 

Operating System

Gentoo

My Question or Issue

I am no longer able to send commands to Spotify using the command line, similar to https://community.spotify.com/t5/Desktop-Linux/Can-t-control-spotify-via-command-line/m-p/4405636. Note that I built the latest testing ebuild from Gentoo (see https://packages.gentoo.org/packages/media-sound/spotify).

My expectation

I expected to continue to control Spotify by using playerctl which I use to bind my keboard multimedia keys with.

How to reproduce

Verify that Spotify is indeed running:

➜  ~ ps -e | grep spotify
                         
30739 ?        00:02:15 spotify
30742 ?        00:00:00 spotify
30789 ?        00:00:00 spotify
30810 ?        00:01:31 spotify

And then finding out D-Bus doesn't see it:

➜  ~ dbus-send --session --dest=org.freedesktop.DBus --type=method_call --print-reply /org/freedesktop/DBus org.freedesktop.DBus.ListNames
method return time=1531736077.269027 sender=org.freedesktop.DBus -> destination=:1.7151 serial=3 reply_serial=2             
   array [
      string "org.freedesktop.DBus"
      string ":1.7"
      string "org.freedesktop.ReserveDevice1.Audio0"
      string ":1.60"
      string ":1.8"
      string ":1.61"
      string ":1.9"
      string ":1.62"
      string "org.gnome.GConf"
      string "org.a11y.Bus"
      string ":1.10"
      string ":1.57"
      string "org.mozilla.firefox.ZGVmYXVsdA__"
      string "org.pulseaudio.Server"
      string "org.PulseAudio1"
      string ":1.2"
      string ":1.3"
      string ":1.7151"
      string ":1.4"
      string ":1.5"
      string "ca.desrt.dconf"
      string ":1.6"
   ]

As a result, playerctl cannot find it:

➜  ~ playerctl -l                                                                                                                         
No players were found

And then trying to toggle play-pause, in vain:

➜  ~ playerctl -p spotify play-pause
An error occurred: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.mpris.MediaPlayer2.spotify was not provided by any .service files

I'm not exactly sure where the root of this problem exists, but I'm guessing Spotify doesn't fully register itself with D-Bus?