bootc install to-existing-root fails with multiple backing devices

[henrywang]

Run podman run --rm --privileged --pid=host -v /:/target -v /dev:/dev -v /var/lib/containers:/var/lib/containers --security-opt label=type:unconfined_t quay.io/redhat_emp1/bootc-workflow-test:jjj0 bootc install to-existing-root on nvidia-jetson-agx-orin board with LVM configured failed with error Installing to filesystem: Found multiple parent devices /dev/mmcblk0 and /dev/nvme0n1; not currently supported.

This nvidia board has one SD/mmc and one nvme as disks. Bootc install does not support two disks?

bootc version: bootc-0.1.9-4.el9.aarch64

fdisk log:

Disk /dev/nvme0n1: 465.76 GiB, 500107862016 bytes, 976773168 sectors
    Disk model: Force MP600
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disklabel type: gpt
    Disk identifier: 957723F9-C6E8-4189-8CF9-D456F380FFFC
  
    Device         Start       End   Sectors   Size Type
    /dev/nvme0n1p1  2048 976773119 976771072 465.8G Linux LVM
  
  
    Disk /dev/mmcblk0: 59.28 GiB, 63652757504 bytes, 124321792 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disklabel type: gpt
    Disk identifier: E629D5BD-48A9-4041-9A5E-E04E9615BD5A
  
    Device           Start       End   Sectors  Size Type
    /dev/mmcblk0p1    2048   1230847   1228800  600M EFI System
    /dev/mmcblk0p2 1230848   3327999   2097152    1G Linux filesystem
    /dev/mmcblk0p3 3328000 124319743 120991744 57.7G Linux LVM
  
  
    Disk /dev/mmcblk0boot0: 31.5 MiB, 33030144 bytes, 64512 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
  
  
    Disk /dev/mmcblk0boot1: 31.5 MiB, 33030144 bytes, 64512 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
  
  
    Disk /dev/mapper/cs_nvidia--jetson--agx--orin--03-root: 70 GiB, 75161927680 bytes, 146800640 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
  
  
    Disk /dev/mapper/cs_nvidia--jetson--agx--orin--03-swap: 30.74 GiB, 33009172480 bytes, 64471040 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
  
  
    Disk /dev/mapper/cs_nvidia--jetson--agx--orin--03-home: 422.71 GiB, 453878218752 bytes, 886480896 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes

[cgwalters]

Ah yes, as the comment in the code says that's generally only required for a grub installation.

Yeah, we should be able to fix this by making the backing_device an Option<T> all the way down into the bootloader install.