[Bug 1896498] [NEW] Ubuntu installer failed while trying "fresh" install over existing instalation on btrfs

[João Manuel Rodrigues]

Public bug reported:

I have a previous installation of Ubuntu 16.04.
My disk has 2 GPT partitions:
/dev/sda1   for /boot/efi
/dev/sda2  btrfs  with 2 subvolumes: @ mounted as /, @home mounted as /home.

I tried a fresh install of Ubuntu 20.04.1.  I selected manual
partitioning and /dev/sda1 was recognized as Boot/efi.  I had to select
/dev/sda2 and specify "mount as" / (there is no better alternative).  I
proceeded and verified on a terminal that the installer detected the
subvolumes just fine:

    ubuntu at ubuntu:~$ mount | grep sda
    /dev/sda2 on /target type btrfs (rw,relatime,ssd,space_cache,subvolid=257,subvol=/@)
    /dev/sda1 on /target/boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro)
    /dev/sda2 on /target/home type btrfs (rw,relatime,ssd,space_cache,subvolid=258,subvol=/@home)

The instalation went on to copy files, all seemed fine.  When the step
"Creating a user" was reached, the installer crashed with an unspecified
error.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubiquity 20.04.15.2
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27.4
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.445.1
Date: Mon Sep 21 15:51:47 2020
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

** Affects: ubiquity (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug focal ubiquity-20.04.15.2 ubuntu

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to ubiquity in Ubuntu.
https://bugs.launchpad.net/bugs/1896498

Title:
  Ubuntu installer failed while trying "fresh" install over existing
  instalation on btrfs

Status in ubiquity package in Ubuntu:
  New

Bug description:
  I have a previous installation of Ubuntu 16.04.
  My disk has 2 GPT partitions:
  /dev/sda1   for /boot/efi
  /dev/sda2  btrfs  with 2 subvolumes: @ mounted as /, @home mounted as /home.

  I tried a fresh install of Ubuntu 20.04.1.  I selected manual
  partitioning and /dev/sda1 was recognized as Boot/efi.  I had to
  select /dev/sda2 and specify "mount as" / (there is no better
  alternative).  I proceeded and verified on a terminal that the
  installer detected the subvolumes just fine:

      ubuntu at ubuntu:~$ mount | grep sda
      /dev/sda2 on /target type btrfs (rw,relatime,ssd,space_cache,subvolid=257,subvol=/@)
      /dev/sda1 on /target/boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro)
      /dev/sda2 on /target/home type btrfs (rw,relatime,ssd,space_cache,subvolid=258,subvol=/@home)

  The instalation went on to copy files, all seemed fine.  When the step
  "Creating a user" was reached, the installer crashed with an
  unspecified error.

  ProblemType: Bug
  DistroRelease: Ubuntu 20.04
  Package: ubiquity 20.04.15.2
  ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
  Uname: Linux 5.4.0-42-generic x86_64
  NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
  ApportVersion: 2.20.11-0ubuntu27.4
  Architecture: amd64
  CasperMD5CheckResult: pass
  CasperVersion: 1.445.1
  Date: Mon Sep 21 15:51:47 2020
  InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
  LiveMediaBuild: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
  SourcePackage: ubiquity
  UpgradeStatus: No upgrade log present (probably fresh install)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1896498/+subscriptions