What were you trying to do that didn't work?

While building an install.iso using `podman run ... registry.redhat.io/rhel10/bootc-image-builder:latest ...`, the ISO is generated without errors, and the installation of a new VM works well. Despite no update is available, the `bootc upgrade --check` command shows an update is available with new layers, with an (unrelated) error while trying to update_timestamps.

The issue in question does NOT happen when deploying the very same image with the standard RHEL ISO with a dedicated kickstart using the `ostreecontainer` command.

What is the impact of this issue to you?

Unable to determine if an update is available with `bootc upgrade --check`.

Please provide the package NVR for which the bug is seen:

registry.redhat.io/rhel10/bootc-image-builder:latest

bootc-1.8.0-2.el10_1.x86_64

How reproducible is this bug?:

Always

Steps to reproduce

1. podman run --rm --privileged --pull=newer --security-opt label=type:unconfined_t    -v ./config.toml:/config.toml:ro -v ./output:/output -v /var/lib/containers/storage:/var/lib/containers/storage registry.redhat.io/rhel10/bootc-image-builder:latest --type iso  --config /config.toml quay.io/rhn-support-cbesson/rhel10-test

1. Install a VM using the generated artifact located in 

   output/buildiso/install.iso

1. Run `bootc upgrade --check` and observe the problematic output.

Expected results

# bootc status --json | jq -r '.status.booted.image.imageDigest'
sha256:c93b46359ddf2394ea54bee53891cc1f99f24bf6ae05f78312618ef33ab59aea

# bootc upgrade --check
No changes in: docker://quay.io/rhn-support-cbesson/rhel10-test

Actual results

# bootc upgrade --check
Update available for: docker://quay.io/rhn-support-cbesson/rhel10-test
  Version: 10.1
  Digest: sha256:c93b46359ddf2394ea54bee53891cc1f99f24bf6ae05f78312618ef33ab59aea
Total new layers: 68    Size: 869.8 MB
Removed layers:   0     Size: 0 bytes
Added layers:     0     Size: 0 bytes
error: Upgrading: Updating storage root mtime: update_timestamps: No such file or directory (os error 2)

# bootc upgrade
Fetched layers: 0 B in 0 seconds (0 B/s)    
No update available.

NOTE: to check if an upgrade is really available, I can do the following:

[ "$(boot status --json | jq -r '.status.booted.image.imageDigest')" != "$(skopeo inspect docker://quay.io/rhn-support-cbesson/rhel10-test | jq -r .Digest)" ] && echo UPDATE || echo NO_UPDATE