Installation without formatting errors on adduser 'Only one or two names allowed.'

[Daniil Tarasov]

Use old partitions of ubuntu 20.04.3 for new installation without formatting

ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: ubiquity 21.10.10
ProcVersionSignature: Ubuntu 5.13.0-19.19-generic 5.13.14
Uname: Linux 5.13.0-19-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu70
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.465
CurrentDesktop: ubuntu:GNOME
Date: Tue Oct 19 22:56:18 2021
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 21.10 "Impish Indri" - Release amd64 (20211012)
ProcEnviron:
 LANGUAGE=en_US.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 LC_NUMERIC=C.UTF-8
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[Sebastien Bacher (seb128)]

The error in the log seems to be

Oct 19 15:54:05 ubuntu user-setup: adduser: Only one or two names allowed.
Oct 19 15:54:05 ubuntu ubiquity: chpasswd: (user ) pam_chauthtok() failed, error:
Oct 19 15:54:05 ubuntu ubiquity: Authentication token manipulation error