Bug#1124118: base-passwd: Desktop users not added to render group during installation

[Kristjan <kristjan.schmidt@googlemail.com>]

Package: base-passwd
Version: 3.6.8
Severity: normal
Tags: d-i
X-Debbugs-Cc: kristjan.schmidt@googlemail.com, debian-boot@lists.debian.org

Dear Maintainer,

After a fresh Debian Testing installation (installer build 20250803+deb13u1) 
with GNOME desktop (task-gnome-desktop), the created user was not added to 
the 'render' group, although the group exists in the system.

What led up to the situation?
* Standard Debian Testing netinstall with GNOME desktop task selected
* User created during installation process

What was the outcome?
* User is member of: cdrom floppy audio dip video plugdev users netdev 
  scanner bluetooth lpadmin input
* The 'render' group exists (GID 992) but is completely empty
* Vulkan applications fail with errors like:
  "Gdk-WARNING: Vulkan: Could not open device /dev/dri/renderD128: 
   Invalid argument (VK_ERROR_INCOMPATIBLE_DRIVER)"

What outcome did you expect?
* Desktop users should be automatically added to the 'render' group during
  installation, similar to how they are added to the 'video' group
* The 'render' group is required for GPU computing and Vulkan applications
  to access /dev/dri/renderD* devices

Workaround:
* sudo usermod -aG render $USER
* logout/login

This likely affects desktop installations where the user was created during
the installation process, preventing users from using Vulkan or GPU-accelerated 
applications without elevated privileges.

Best regards
Kristjan

-- System Information:
Debian Release: forky/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 6.17.12+deb14-amd64 (SMP w/24 CPU threads; PREEMPT)
Kernel taint flags: TAINT_USER
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages base-passwd depends on:
ii  libc6              2.42-6
ii  libdebconfclient0  0.282+b2
ii  libselinux1        3.9-4+b1

Versions of packages base-passwd recommends:
ii  debconf [debconf-2.0]  1.5.91

base-passwd suggests no packages.

-- debconf information:
  base-passwd/user-change-gecos: true
  base-passwd/user-add: true
  base-passwd/user-change-uid: true
  base-passwd/user-change-gid: true
  base-passwd/group-add: true
  base-passwd/group-remove: true
  base-passwd/user-change-home: true
  base-passwd/user-change-shell: true
  base-passwd/group-move: true
  base-passwd/group-change-gid: true
  base-passwd/user-move: true
  base-passwd/user-remove: true