https://bugs.kde.org/show_bug.cgi?id=521196
Bug ID: 521196
Summary: Snap package completely non-functional: unable to
PREVENT MEDIA REMOVAL - burning impossible
Classification: Applications
Product: k3b
Version First unspecified
Reported In:
Platform: Other
OS: Linux
Status: REPORTED
Severity: major
Priority: NOR
Component: Burning/Hardware
Assignee: [email protected]
Reporter: [email protected]
CC: [email protected], [email protected]
Target Milestone: ---
Created attachment 192983
--> https://bugs.kde.org/attachment.cgi?id=192983&action=edit
Proof of non existing mailing list
DESCRIPTION
The K3b Snap package (26.4.1) fails to burn any disc due to the Snap
sandbox blocking the SCSI command PREVENT MEDIA REMOVAL. This makes
the Snap package completely useless for its core purpose — burning
optical media. This is not an edge case but affects every user on
Ubuntu 22.04 LTS based systems who installs K3b via Snap, which is
the only way to get a version newer than 21.12.3 (2021) on these systems.
STEPS TO REPRODUCE
1. Install K3b via Snap on Ubuntu 22.04 / Zorin OS 17.3
2. Insert a blank BD-RE disc (tested: Verbatim BD-RE 25GB)
3. Create a data project and attempt to burn
OBSERVED RESULT
Burning fails immediately (after 2 seconds) with:
:-( unable to PREVENT MEDIA REMOVAL: Operation not permitted
mkisofs aborted.
Workarounds attempted — all failed:
- sudo snap connect k3b:optical-drive :optical-drive
- sudo chmod 666 /dev/sr0
- sudo usermod -aG cdrom $USER
None of these resolve the issue. The Snap confinement fundamentally
blocks the required low-level SCSI hardware access regardless of
permissions granted on the host system.
EXPECTED RESULT
Disc burns successfully.
SOFTWARE/OS VERSIONS
Operating System: Zorin OS 17.3 (Ubuntu 22.04 LTS / Jammy Jellyfish)
Kernel: 6.8.0-94-generic
K3b: 26.4.1 (Snap package, /snap/k3b/47/)
Burner: ASUS SBW-06D5H-U (external USB Blu-ray burner)
growisofs: 7.1
mkisofs: 1.1.11
ADDITIONAL INFORMATION
This is a systemic problem affecting both Snap and Flatpak:
1. FLATPAK: A Flatpak submission for K3b was attempted on Flathub
(PR #4395) and was closed in March 2025 without resolution after
nearly 2 years of work. The core finding: Flatpak strips group
memberships (e.g. cdrom group) inside the sandbox, making it
impossible to grant the necessary /dev/sr0 write permissions.
Reference: https://github.com/flathub/flathub/pull/4395
2. SNAP: The same fundamental issue exists in Snap — group
memberships and device permissions are not properly passed through
to the sandboxed application.
3. IMPACT: On Ubuntu 22.04 LTS (supported until 2027), the native
apt repository only provides K3b 21.12.3 from 2021. The Snap package
is the only officially promoted upgrade path — but it does not work
for burning. This means all improvements and bug fixes since 2021
never reach the majority of Ubuntu LTS users.
4. WORKAROUND: Installing K3b 22.04.3 from the Kubuntu Backports PPA
as a native .deb package works correctly. However this requires
technical knowledge that most users do not have.
5. MAILING LIST: The official [email protected] mailing list linked on the
K3b product page appears to be dead — Mailman returns an error
stating the list does not exist.
The Snap and Flatpak packages give users the false impression that
K3b works on their system, when in reality burning is completely
broken. A prominent warning on the Snap Store listing and the K3b
website would at minimum prevent user frustration.
Tested hardware confirmed working with native .deb package:
ASUS SBW-06D5H-U external USB Blu-ray burner on Linux kernel 6.8.0
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