gst-device-monitor-1.0 on raspbian

[Jack]

Hello,

I installed gstreamer (GStreamer 1.14.4) on Raspbain Buster :

$ sudo apt install libgstreamer1.0-0 gstreamer1.0-plugins-base
gstreamer1.0-plugins-good gstreamer1.0-plugins-bad
gstreamer1.0-plugins-ugly gstreamer1.0-libav gstreamer1.0-doc
gstreamer1.0-tools gstreamer1.0-x gstreamer1.0-alsa
gstreamer1.0-pulseaudio gstreamer1.0-plugins-base-apps

gstreamer1.0-plugins-base-apps is installed so I can run :
$ gst-device-monitor-1.0

but I get :

Probing devices...

Failed to start device monitor!

Any clue to solve this problem ?
++

Jack