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

Reboot after bootc install --to-filesystem in was run by anaconda

What is the impact of this issue to you?

When the system is rebooted after installation, the system brings up grub shell instead of a boot menu.

This bug blocks the Anaconda bootc feature for the next RHEL 10 release.

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

It is broken in this snapshot:

https://download.copr.fedorainfracloud.org/results/rhcontainerbot/bootc/fedora-rawhide-x86_64/09695947-bootc/

This previous snapshot works: https://download.copr.fedorainfracloud.org/results/rhcontainerbot/bootc/fedora-rawhide-x86_64/09684678-bootc/

The bug has been traced to this PR: https://github.com/bootc-dev/bootc/pull/1662#issuecomment-3429499580

Since that PR, at least this necessary line in boot/grub2/grub.cfg is missing: 
blscfg
 

How reproducible is this bug?:

Everytime.

Steps to reproduce

We are using anaconda from this PR: https://github.com/rhinstaller/anaconda/pull/6298

To make this easier to test, we have a prebuilt install ISO and script to run it:

1. dnf install qemu-img qemu-system-x86-core
2. Download boot-updated.iso and run-anaconda.sh from https://drive.google.com/drive/folders/1kD8u1WQef6QXPo4K7VIwljL0IQArpkmr
3. mkdir -p result/iso
4. mv boot-updated.iso result.iso/
5. ./run-anaconda.sh  # This will run the iso via qemu
6. Select Install Fedora from the boot menu.  This will start Anaconda.  There is a kickstart file on the image which will do a bootc install of quay.io/fedora-testing/fedora-bootc:rawhide-standard
7. When the install is complete, press the  [Reboot System]button to reboot
8. Notice that the machine drops you to grub shell instead of proceeding to the boot menu.

Expected results

Reboot to a login prompt.

Actual results

The machine drops you to grub shell instead of proceeding to the boot menu.