error: file `/boot/vmlinuz-6.9.1-060901-generic' not found.

[iconoclasthero]

I tried to install rhino alongside ubuntu 22.04 before and had very bad luck and my original OS stopped booting... so i had the rhino installer just install what was needed for the root part on btrfs not installing anything on boot, efi, etc., expecting that whatever it did, I could also do, but do right for my system.... upon trying to boot into p10, rhino:

error: file `/boot/vmlinuz-6.9.1-060901-generic' not found.
error: you need to load the kernel first.

Press any key to continue.

from 22.04 with p10 mounted @/mnt/rhino

root@latitude:/mnt/rhino/boot# pwd; ll; update-grub; grep rhino /etc/fstab
/mnt/rhino/boot

total 90852
drwxr-xr-x 1 root root      326 Jun  7 09:25 ./
drwxr-xr-x 1 root root      260 May 27 16:17 ../
-rw-r--r-- 1 root root   287909 May 17 06:38 config-6.9.1-060901-generic
drwxr-xr-x 1 root root       38 Jun  7 09:57 grub/
lrwxrwxrwx 1 root root       31 May 27 16:17 initrd.img -> initrd.img-6.9.1-060901-generic
-rw------- 1 root root 69032752 Jun  7 09:25 initrd.img-6.9.1-060901-generic
lrwxrwxrwx 1 root root       31 May 27 16:17 initrd.img.old -> initrd.img-6.9.1-060901-generic
-rw------- 1 root root  8710205 May 17 06:38 System.map-6.9.1-060901-generic
lrwxrwxrwx 1 root root       28 May 27 16:17 vmlinuz -> vmlinuz-6.9.1-060901-generic
-rw------- 1 root root 14977240 Jun  7 09:24 vmlinuz-6.9.1-060901-generic
lrwxrwxrwx 1 root root       28 May 27 16:17 vmlinuz.old -> vmlinuz-6.9.1-060901-generic

Sourcing file `/etc/default/grub'
Sourcing file `/etc/default/grub.d/init-select.cfg'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-6.5.0-35-generic
Found initrd image: /boot/initrd.img-6.5.0-35-generic
Found linux image: /boot/vmlinuz-6.5.0-28-generic
Found initrd image: /boot/initrd.img-6.5.0-28-generic
Memtest86+ needs a 16-bit boot, that is not available on EFI, exiting
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
Found Windows Boot Manager on /dev/nvme0n1p1@/EFI/Microsoft/Boot/bootmgfw.efi
Found Ubuntu Oracular Oriole (development branch) (24.10) on /dev/nvme0n1p10
Adding boot menu entry for UEFI Firmware Settings ...
Detecting snapshots ...
No snapshots found.
If you think an error has occurred, please file a bug report at "https://github.com/Antynea/grub-btrfs"
Unmount /tmp/grub-btrfs.Zl4eJwAc1H .. Success
done

UUID=f43f84e5-3df0-486f-b26b-8a657a170a61 /mnt/rhino        btrfs   defaults,subvol=@        0       2
root@latitude:/mnt/rhino/boot# 
# /mnt/rhino was on /dev/nvme0n1p10

interestingly, that p8 partition is listed as grub2 core.img in gparted

root@latitude:/mnt/rhino/boot# lsblk; blkid
NAME         MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
loop0          7:0    0 162.5M  1 loop /snap/chromium/2866
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loop21         7:21   0   476K  1 loop /snap/snapd-desktop-integration/157
sda            8:0    1     0B  0 disk 
nvme0n1      259:0    0 476.9G  0 disk 
├─nvme0n1p1  259:1    0   498M  0 part /boot/efi
├─nvme0n1p2  259:2    0   128M  0 part 
├─nvme0n1p3  259:3    0  46.6G  0 part 
├─nvme0n1p4  259:4    0   821M  0 part 
├─nvme0n1p5  259:5    0     8G  0 part [SWAP]
├─nvme0n1p6  259:6    0  53.7G  0 part /home
├─nvme0n1p7  259:7    0 272.8G  0 part /library
├─nvme0n1p8  259:8    0     1M  0 part 
├─nvme0n1p9  259:9    0  44.4G  0 part /var/snap/firefox/common/host-hunspell
│                                      /
└─nvme0n1p10 259:10   0    50G  0 part /mnt/rhino
/dev/nvme0n1p9: LABEL="ubuntu" UUID="399aa2b9-10b7-4491-90c5-00e53b6a0484" UUID_SUB="75f90ab8-bfe9-49de-925b-651714831e71" BLOCK_SIZE="4096" TYPE="btrfs" PARTLABEL="ubuntu" PARTUUID="ebe9fd3b-0795-4fc3-bed1-9b998be78725"
/dev/nvme0n1p7: LABEL="library" UUID="abc0285f-3137-4b55-914b-3ce7fc4f1254" UUID_SUB="cb36fc24-a25e-438d-ae31-ea586d01ed30" BLOCK_SIZE="4096" TYPE="btrfs" PARTLABEL="library" PARTUUID="30740cd5-64f1-48cd-b967-9ae0782b9fe7"
/dev/nvme0n1p5: UUID="1e85e0e4-85cc-4aea-9e23-9234be9ec5d9" TYPE="swap" PARTLABEL="swap" PARTUUID="31c7edb9-b4bd-4d96-8877-fc2b405c5183"
/dev/nvme0n1p1: LABEL_FATBOOT="ESP" LABEL="ESP" UUID="BA6F-2F68" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI system partition" PARTUUID="a895c7c7-78fe-4381-b3ab-16dfe013345e"
/dev/nvme0n1p10: UUID="f43f84e5-3df0-486f-b26b-8a657a170a61" UUID_SUB="7080a891-810f-4245-aeec-8ac1f779546a" BLOCK_SIZE="4096" TYPE="btrfs" PARTLABEL="rhino" PARTUUID="30f05606-48be-4111-b213-9fb0785ec12a"
/dev/nvme0n1p6: LABEL="home" UUID="90ef8c9a-704c-468c-bf13-b56770c10a89" UUID_SUB="c356c5ee-9624-42bb-a1d7-e04397e5b483" BLOCK_SIZE="4096" TYPE="btrfs" PARTLABEL="home" PARTUUID="3ef3aef2-c46e-4595-956a-61ed9deae931"
/dev/nvme0n1p8: PARTUUID="87fabc2f-3687-47b8-a673-1ddc8c8ed1bc"
/dev/loop1: TYPE="squashfs"
/dev/loop19: TYPE="squashfs"

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