[BUG] Missing xz-utils are required to install calibre mod

[jorti]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

Calibre docker mod fails to install as it has to untar a file compressed with xz and the xz-utils package is not installed in the image.

Expected Behavior

Calibre mod installs without errors.

Steps To Reproduce

1. Run container with image lscr.io/linuxserver/calibre-web:latest and the following env variables:

PUID=1000
PGID=1000
DOCKER_MODS=linuxserver/mods:universal-calibre

2. Check the container logs

Environment

- OS: Fedora CoreOS 43.20251110.3.1
- How docker service was installed: I'm using podman-5.6.2-1.fc43.x86_64

CPU architecture

x86-64

Docker creation

[
  "/usr/bin/podman",
  "run",
  "--name",
  "calibre-web",
  "--replace",
  "--rm",
  "--cgroups=split",
  "--network",
  "calibre",
  "--sdnotify=conmon",
  "-d",
  "--security-opt=no-new-privileges",
  "--userns",
  "auto:uidmapping=0:2147656277:1024,gidmapping=0:2147656277:1024",
  "-v",
  "calibre-web:/config:U,Z",
  "-v",
  "/srv/ebooks:/calibre-library:Z",
  "-v",
  "/srv/calibre/ingest:/book-ingest:z",
  "--label",
  "io.containers.autoupdate=registry",
  "--env",
  "DOCKER_MODS=linuxserver/mods:universal-calibre",
  "--env",
  "PGID=1000",
  "--env",
  "PUID=1000",
  "--label",
  "homepage.description=eBooks",
  "--label",
  "homepage.group=Multimedia",
  "--label",
  "homepage.href=https://libros.example.com/",
  "--label",
  "homepage.icon=calibre-web.svg",
  "--label",
  "homepage.name=Calibre Web",
  "--label",
  "traefik.docker.network=calibre",
  "--label",
  "traefik.enable=true",
  "--label",
  "traefik.http.routers.calibre-web.entrypoints=websecure",
  "--label",
  "traefik.http.routers.calibre-web.middlewares=external-middlewares@file,authelia@docker",
  "--label",
  "traefik.http.routers.calibre-web.rule=Host(`libros.example.com`)",
  "--label",
  "traefik.http.routers.calibre-web.tls=true",
  "--label",
  "traefik.http.routers.calibre-web.tls.certresolver=le-prod",
  "--memory",
  "1g",
  "lscr.io/linuxserver/calibre-web:latest"
]

Container logs

[mod-init] Running Docker Modification Logic
[mod-init] Adding linuxserver/mods:universal-calibre to container
[mod-init] Downloading linuxserver/mods:universal-calibre from lscr.io
[mod-init] Installing linuxserver/mods:universal-calibre
[mod-init] linuxserver/mods:universal-calibre applied to container
[migrations] started
[migrations] no migrations found
───────────────────────────────────────

      ██╗     ███████╗██╗ ██████╗
      ██║     ██╔════╝██║██╔═══██╗
      ██║     ███████╗██║██║   ██║
      ██║     ╚════██║██║██║   ██║
      ███████╗███████║██║╚██████╔╝
      ╚══════╝╚══════╝╚═╝ ╚═════╝

   Brought to you by linuxserver.io
───────────────────────────────────────

To support the app dev(s) visit:
Calibre-Web: https://paypal.me/calibreweb

To support LSIO projects visit:
https://www.linuxserver.io/donate/

───────────────────────────────────────
GID/UID
───────────────────────────────────────

User UID:    1000
User GID:    1000
───────────────────────────────────────
**** Adding calibre dependencies to package install list ****
[pkg-install-init] **** Installing all mod packages ****
E: setgroups 65534 failed - setgroups (22: Invalid argument)
E: setegid 65534 failed - setegid (22: Invalid argument)
Reading package lists...
E: setgroups 65534 failed - setgroups (22: Invalid argument)
E: setegid 65534 failed - setegid (22: Invalid argument)
E: Method gave invalid 400 URI Failure message: Failed to setgroups - setgroups (22: Invalid argument)
E: Method http has died unexpectedly!
E: Sub-process http returned an error code (112)
Reading package lists...
Building dependency tree...
Reading state information...
Package xz-utils is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Unable to locate package libxtst6
E: Unable to locate package libxrandr2
E: Unable to locate package libxkbfile1
E: Unable to locate package libxcomposite1
E: Unable to locate package libopengl0
E: Unable to locate package libnss3
E: Unable to locate package libxkbcommon0
E: Unable to locate package libegl1
E: Unable to locate package libxdamage1
E: Unable to locate package libgl1
E: Unable to locate package libglx-mesa0
E: Package 'xz-utils' has no installation candidate
tar (child): xz: Cannot exec: No such file or directory
tar (child): Error is not recoverable: exiting now
tar: Child returned status 2
tar: Error is not recoverable: exiting now
Installing Calibre version v8.16.2
/etc/s6-overlay/s6-rc.d/init-mod-universal-calibre-setup/run: line 26: /app/calibre/calibre_postinstall: No such file or directory
**** The 2 warnings above about setting up completion and desktop integration are expected and harmless. You can safely ignore them. ****
[custom-init] No custom files found, skipping...
[2025-12-21 07:50:44,124]  WARN {warnings.py:110} /lsiopy/lib/python3.12/site-packages/pycountry/__init__.py:10: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
  import pkg_resources

Connection to localhost (::1) 8083 port [tcp/*] succeeded!
[ls.io-init] done.

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[jorti]

I found the problem. I'm using userns and I need to allocate 65535 UIDs. That allows the init script to run.