DRM permission denied

I have an gstreamer based application which could play video streams by URL link. Atm I’m trying to pack it into Snap package. My snapcraft.yaml:

name: hello
version: '1.0'
base: core20
summary: Your application summary
description: Your application description
confinement: devmode
grade: stable
         
plugs:
  network:
    interface: network

apps:
  hello:
    command: ./bin/hello
    plugs: 
       - home
       - desktop
       - desktop-legacy
       - wayland
       - unity7
       - alsa
       - audio-playback
       - network
       - screen-inhibit-control
    environment:
      LD_LIBRARY_PATH: $SNAP/usr/lib/x86_64-linux-gnu/pulseaudio:$LD_LIBRARY_PATH
      GST_PLUGIN_SCANNER: $SNAP/usr/lib/x86_64-linux-gnu/gstreamer1.0/gstreamer-1.0/gst-plugin-scanner
      GST_PLUGIN_SYSTEM_PATH: $SNAP/usr/lib/x86_64-linux-gnu/gstreamer-1.0

parts:
  hello:
    plugin: cmake
    source-type: git
    source: https://github.com/hello
    override-build: |
      cd ../src
      cmake -S . -B build
      cmake --build build
      mkdir $SNAPCRAFT_PART_INSTALL/bin
      cp -p build/hello$SNAPCRAFT_PART_INSTALL/bin
      cd ..
      rm -rf .src
    build-packages: 
      - build-essential
      - pkg-config
      - libgstreamer-plugins-base1.0-dev
      - libglib2.0-dev
    stage-packages:
      - gstreamer1.0-libav
      - gstreamer1.0-alsa
      - gstreamer1.0-pulseaudio
      - gstreamer1.0-plugins-bad
      - gstreamer1.0-plugins-good
      - gstreamer1.0-plugins-ugly
      - gstreamer1.0-plugins-base
      - libgl1
      - libglvnd0
      - libglx0
      - libpulse0
      - libjson-glib-1.0-0
      - libasound2
      - alsa-utils
      - alsa-oss
      - xserver-xorg-legacy
      - libdrm2
      - libdrm-dev

But then I run this hello snap package I’m getting this message:

0:00:06.380954713 60423 0x55687d6262a0 WARN                 kmssink gstkmssink.c:1670:gst_kms_sink_show_frame:<video-sink-actual-sink-kms> error: drmModeSetPlane failed: Permission denied (-13)

I understand that my Snap package has no some DRM permissions but could it be work arounded?

Is there any particular reason that you use the older core20 instead of core22 ?

I’d also consider using the gnome extension, that should bring along the gstreamer framework so you could drop most stage packages and interface plugs fr9m your snapcraft.yaml

I tried core22 but it hangs on “launching instance…” - issue is very same to this one but proposed snap restart multipass solution does not help.

Upd. core22 started to work somehow after several attempts. But I still receive the same drm related error.