Subiquity installs may fail when creating an unformatted partition

[Dan Bungert]

We have multiple reports in private bugs about Subiquity installs failing at the Curtin partitioning step.

The symptom for that would be the following in curtin-install.log

        finish: cmd-install/stage-partitioning/builtin/cmd-block-meta: FAIL: curtin command block-meta
        Traceback (most recent call last):
          File "/snap/ubuntu-desktop-bootstrap/75/lib/python3.10/site-packages/curtin/commands/main.py", line 202, in main
            ret = args.func(args)
          File "/snap/ubuntu-desktop-bootstrap/75/lib/python3.10/site-packages/curtin/log.py", line 97, in wrapper
            return log_time("TIMED %s: " % msg, func, *args, **kwargs)
          File "/snap/ubuntu-desktop-bootstrap/75/lib/python3.10/site-packages/curtin/log.py", line 79, in log_time
            return func(*args, **kwargs)
          File "/snap/ubuntu-desktop-bootstrap/75/lib/python3.10/site-packages/curtin/commands/block_meta.py", line 127, in block_meta
            return meta_custom(args)
          File "/snap/ubuntu-desktop-bootstrap/75/lib/python3.10/site-packages/curtin/commands/block_meta.py", line 2275, in meta_custom
            handler(command, storage_config_dict, context)
          File "/snap/ubuntu-desktop-bootstrap/75/lib/python3.10/site-packages/curtin/commands/block_meta.py", line 1213, in format_handler
            mkfs.mkfs_from_config(volume_path, info)
          File "/snap/ubuntu-desktop-bootstrap/75/lib/python3.10/site-packages/curtin/block/mkfs.py", line 241, in mkfs_from_config
            mkfs(path, fstype, strict=strict, force=True, uuid=info.get('uuid'),
          File "/snap/ubuntu-desktop-bootstrap/75/lib/python3.10/site-packages/curtin/block/mkfs.py", line 169, in mkfs
            raise ValueError("unsupported fs type '%s'" % fstype)
        ValueError: unsupported fs type ''
        unsupported fs type ''

[Dan Bungert (dbungert)]

We believe this issue has been resolved in Subiquity 24.04.1, which can be obtained on the Ubuntu 24.04 LTS ISOs or as a snap refresh.

If testing from 23.10 or 23.04 Desktop ISOs, due to the snap change from ubuntu-desktop-installer to ubuntu-desktop-provision it is necessary to use the 24.04 Desktop ISO to obtain the fix.

[brian mullan (bmullan)]

I *think* I solved the problem with failures of Ubuntu 24.04 to install.

Using *USB Startup Creator* to create the Install USB is what was causing the failures!

I found 1 person's comment where he was having the exact same failures as myself.
But he switched to Balena-Etcher to create the Install USB for 24.04 and it worked!

So I tried that.
- Downloaded the latest Balena-Etcher .DEB file: https://github.com/balena-io/etcher/releases/tag/v1.19.17
- Installed it.
- Created the USB Installer for 24.04

Using that USB the *install using BTRFS and it... worked !!*

Tried doing the same using EXT4 and it... Worked also!!

I'd used Startup Disk Creator to reburn the 24.04 image and try to install at least 10 times, trying diff file systems,
24.04 Server and 24.04 Desktop with each attempt failing

So it seems *something about the use of USB Startup Creator* appears to be the root cause.
since a USB Installer created by Balena-Etcher using the exact same .ISO worked 1st time successfully.