ubiquity --no-bootloader crashes trying install to sdb using gpt, swap,efi, and btrfs partition

[Lorin K]

expected: no crash
actual: crash shortly after the partition prompt after clicking "Install Now".

note i tried twice. first with crypt then without. Even re-formatted and tried without crypt and got a crash again.

Was following tutorial by mutschler.dev titled "Ubuntu Desktop 20.04: installation guide with btrfs-luks full disk encryption including /boot and auto-apt snapshots with Timeshift"

lsb_release -rd
Description: Ubuntu 22.04.1 LTS
Release: 22.04

apt-cache policy ubiquity
ubiquity:
  Installed: 22.04.17
  Candidate: 22.04.19
  Version table:
     22.04.19 500
        500 http://archive.ubuntu.com/ubuntu jammy-updates/main amd64 Packages
 *** 22.04.17 100
        100 /var/lib/dpkg/status
     22.04.15 500
        500 http://archive.ubuntu.com/ubuntu jammy/main amd64 Packages

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: ubiquity 22.04.17 [modified: lib/partman/fstab.d/btrfs lib/partman/mount.d/70btrfs]
ProcVersionSignature: Ubuntu 5.15.0-43.46-generic 5.15.39
Uname: Linux 5.15.0-43-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu82.1
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.470
Date: Wed May 10 10:48:03 2023
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 22.04.1 LTS "Jammy Jellyfish" - Release amd64 (20220809.1)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
 LC_NUMERIC=C.UTF-8
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[Lorin K (lorink)]

similar error:
https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1077129

[Lorin K (lorink)]

from UbiquitySyslog.txt:
May 10 08:47:13 ubuntu ubiquity[64126]: Starting the installation
May 10 08:47:13 ubuntu ubiquity[64126]: debconffilter_done: ubiquity.components.partman_commit (current: ubi-usersetup)
May 10 08:47:13 ubuntu ubiquity: Traceback (most recent call last):
May 10 08:47:13 ubuntu ubiquity: File "/usr/share/ubiquity/install.py", line 769, in <module>
May 10 08:47:13 ubuntu ubiquity: install = Install()
May 10 08:47:13 ubuntu ubiquity: File "/usr/share/ubiquity/install.py", line 69, in __init__
May 10 08:47:13 ubuntu ubiquity: assert os.path.ismount(self.target), \
May 10 08:47:13 ubuntu ubiquity: AssertionError: Failed to mount the target: /target

[Ingo Breßler (ibressler)]

Hello everyone,
I ran into this error too, a while ago. It is caused by the customized btrfs options in the referred guide ( https://mutschler.dev/linux/ubuntu-btrfs-20-04/#step-3-optional-optimize-mount-options-for-ssd-or-nvme-drives ). btrfs was not happy with the *space_cache* option added in the partman config and could not mount the volume. This failure is not forwarded to the ubiquity log. It just finds the mount point not mounted. So, please test the options first, supported options might change with newer/other versions of btrfs/kernels (considering that this guide was for 20.04 and I was installing 23.10 ;)
Best regards!
Ingo

[reborn-cz (reborn-cz)]

(ibressler) you are right, thank you very much, it works with the space_cache=v2