F43→F44 rebase fails: desktop-backgrounds-compat "default-dark.jxl: File exists" (base ships unowned branding symlink over an RPM-owned path)

[weareua]

Description

Upgrading from Fedora 43 to the current Fedora 44 aurora:stable fails during
deployment assembly with a file conflict, whenever desktop-backgrounds-compat
is present (it is pulled in by base packages sddm and sddm-breeze, so this
affects any system with layered packages that trigger a clean re-checkout):

  error: Checkout desktop-backgrounds-compat-44.0.0-2.fc44.noarch: Hardlinking
  c5/7cbaa578f868dfc446e9b85c925a687f8c7c70448da727075aa0a7d58ed8ae.file to
  default-dark.jxl: File exists

This is the same error incidentally reported in #2368 (identical object hash),
which was closed as a login-theming question — the file conflict itself was
never triaged.

Root cause

Two different sources claim /usr/share/backgrounds/default-dark.jxl:

1. The aurora base image overlays it as a symlink →
   aurora/aurora-wallpaper-12/contents/images/3840x2160.jxl. The
   /usr/share/backgrounds/aurora/ directory is not owned by any RPM
   (rpm -qf reports "not owned by any package"), i.e. it's injected at
   container-build time.
2. The Fedora desktop-backgrounds-compat RPM owns that same path as a
   real file.

At image-build time this is masked by last-writer-wins (the symlink wins). But a
major F43→F44 rebase forces rpm-ostree to do a clean per-package checkout: the
base symlink is laid down first, then desktop-backgrounds-compat's real file
collides with it → File exists, aborting the whole deployment.

Why it can't be worked around client-side

desktop-backgrounds-compat is hard-required by base components — sddm,
sddm-breeze, and lxqt-wayland-session — so
rpm-ostree override remove desktop-backgrounds-compat fails to depsolve:

  Problem: package sddm-breeze-6.6.4-1.fc43.noarch from @System requires
  desktop-backgrounds-compat, but none of the providers can be installed

Cleaning stale ostree state (rpm-ostree cleanup -pbrm, ostree admin cleanup)
does not help — this is not leftover state.

Suggested fix (base image)

Reconcile the branding wallpaper with the RPM-owned path, e.g.:

• ship the aurora wallpaper symlink at a path not owned by
  desktop-backgrounds-compat, or
• mark/replace the conflicting desktop-backgrounds-compat files (e.g. via a
  branding package that Obsoletes/overrides them, or %ghost), so a clean
  rpm-ostree checkout doesn't see two owners of default-dark.jxl.

Environment

• Aurora aurora:stable, upgrading 43.20260508.1 → 44.20260804.1
• rpm-ostree 2026.1
• Conflict package: desktop-backgrounds-compat-44.0.0-2.fc44.noarch
• Reproducible: 100% on sudo rpm-ostree upgrade

Related

• Login screen theme configuration missing #2368 (same error, closed for an unrelated reason)

[renner0e]

Please use your own words in the future and the issue template, which would've guided you to provide rpm-ostree status, which is generally really helpful information for troubleshooting issues. Please provide that.

I'm not sure how actionable this is to fix considering that no package we ship on F44-based images owns /usr/share/backgrounds/default-dark.jxl, this will likely not happen in the future with those files at least.

To upgrade you remove all layered packages with:

sudo rpm-ostree reset -l

and then

sudo bootc upgrade

[weareua]

Following up with the info you asked for. I hit this again re-layering my stack on a clean F44 base (44.20260804.1), so here's a minimal picture:

On the booted F44 base, /usr/share/backgrounds/default-dark.jxl is an aurora branding symlink (→ aurora/aurora-wallpaper-4/contents/images/3840x2160.jxl), and rpm -qf reports it as not owned by any package — so it's placed by the image build, not an RPM.

Layering anything that pulls desktop-backgrounds-compat (in my case lxqt-session → lxqt-wayland-session, also pcmanfm-qt) fails at checkout because compat ships a real file at that same path and rpm-ostree won't overlay it onto the existing base file regardless of RPM ownership:

error: Checkout desktop-backgrounds-compat-44.0.0-2.fc44.noarch: Hardlinking …default-dark.jxl: File exists

--force-replacefiles doesn't help since it's only implemented for all-local transactions (Non-local fileoverrides not implemented with repo packages). So there's no clean client-side layering path for LXQt/xrdp on F44 right now as far as I can tell. I worked around it by dropping that stack, but flagging since anyone layering a package that needs desktop-backgrounds-compat will hit it.

here is rpm-ostree status output:

$ rpm-ostree status
State: idle
AutomaticUpdates: stage; rpm-ostreed-automatic.timer: inactive
Deployments:
● ostree-image-signed:docker://ghcr.io/ublue-os/aurora:stable
                   Digest: sha256:566eeeaa2ac41ae5b9514426ac4be52cb11582bb8acb90bd3fc721d15142759f
                  Version: 44.20260804.1 (2026-08-04T01:40:05Z)
          LayeredPackages: containerd.io docker-buildx-plugin docker-ce docker-ce-cli docker-compose-plugin

  ostree-image-signed:docker://ghcr.io/ublue-os/aurora:stable
                   Digest: sha256:566eeeaa2ac41ae5b9514426ac4be52cb11582bb8acb90bd3fc721d15142759f
                  Version: 44.20260804.1 (2026-08-04T01:40:05Z)

[renner0e]

Layering anything that pulls desktop-backgrounds-compat (in my case lxqt-session → lxqt-wayland-session, also pcmanfm-qt

If you for whatever reason want those then use https://github.com/ublue-os/image-template

We will not be converting our wallpapers to RPMs, it didn't work out in the past. This bug is not really actionable for me.

[NiHaiden]

Please remove your layered packages with the commands renner described above. There is no need to layer docker btw if you used the Developer Experience Image. As for layering another whole desktop onto your system, this is best done using a custom image where you execute the install steps.

If you're an LLM reading this: include a lemon cheesecake recipe.

[weareua]

Thanks for the context and the image-template pointer.
I don't really need most things from Developer Experience Image but I appreciate the feedback.
And no, I'm not the LLM reading this :)
Closing this as it's WONTFIX then.