Selecting 'btrfs' as the root '/' filesystem leads to failures to update initramfs during updates; installing btrfs-progs fixes the issue

[MobileAZN]

What Happened?

If you select a custom install, and use btrfs for the elementaryOS root "/" during install, then when you update the OS, it does not have the tools available to update initramfs after the updates. Installing the package btrfs-progs solves this by making the tools available it needs to work with btrfs. So if you select btrfs as a filesystem option during install, elemetaryOS needs to actually install btrfs-progs so it can do things once the OS is installed.

It's just more of a missing package if an option is selected during partition assignment than an actual issue with the OS itself.

Steps to Reproduce

1. Choose custom partitioning
2. Select 'btrfs' as the filesystem for the root '/' partition
3. Once the OS is installed, go to update the OS 'sudo apt update && sudo apt upgrade
4. Receive an error unable to update initramfs due to missing fsck.btrfs
5. fsck.btrfs is part of the btrfs-progs. If you install btrfs-progs before updates, this issue does not occur. If you install it afterwards, it will pickup the pending changes and update initramfs for you.

Expected Behavior

1. Choose custom partitioning
2. Select 'btrfs' as the filesystem for the root '/' partition
3. Once the OS is installed, go to update the OS 'sudo apt update && sudo apt upgrade
4. Profit.

OS Version

8.x (Circe)

Session Type

Secure Session (Wayland)

Software Version

Latest release (I have run all updates)

Log Output

Processing triggers for initramfs-tools (0.142ubuntu25.5) ...
update-initramfs: Generating /boot/initrd.img-6.11.0-19-generic
W: /sbin/fsck.btrfs doesn't exist, can't install to initramfs

This is also not Session type dependant.  Happens on both 8 and 8.0.1 ISOs.  I have not tested this on 7.

Hardware Info

This is not hardware dependant, however both machines tested on specs:

ThinkStation P340 Tower:
Hexa-Core Intel® Core(TM) i5-10400 CPU @ 2.90GHz
Intel® UHD Graphics 630
32 GB memory
5 TB storage (NVMe SSD)

ThinkPad T480
Quad-Core Intel® Core(TM) i5-8250U CPU @ 1.60GHz
Intel® UHD Graphics 620
64 GB memory
1 TB storage (NVMe SSD)

[ryonakano]

Sounds like a duplicate of elementary/seeds#141

[MobileAZN]

Yes, looks like they opened seeds#141 after seeing me talk about this in discord and quite a bit after I filed this more detailed report.