playerctl: skip metada to control music

playerctl-fast.sh

#!/bin/bash

set -euo pipefail

case "${1:-}" in
  next)
    MEMBER=Next
    ;;

  previous)
    MEMBER=Previous
    ;;

  play)
    MEMBER=Play
    ;;

  pause)
    MEMBER=Pause
    ;;

  play-pause)
    MEMBER=PlayPause
    ;;

  *)
    echo "Usage: $0 next|previous|play|pause|play-pause"
    exit 1
    ;;

esac

exec dbus-send                                                \
  --print-reply                                               \
  --dest="org.mpris.MediaPlayer2.$(playerctl -l | head -n 1)" \
  /org/mpris/MediaPlayer2                                     \
  "org.mpris.MediaPlayer2.Player.$MEMBER"

Why is line 34 required? The command seems to not work without it.

I guess that it depends on the player. I'm using this script with an old version of spotifyd. If I remove the --print-reply option, the action is not executed.

Yes, even for me (latest version of spotifyd) it does not work, but I was unable to understand why not printing the reply makes it not work, maybe something to do with dbus or spotifyd.