After selecting the experimental ZFS install option, the install begins. However after a few messages about creating EXT4 partitions, the installer fails and aborts the install.
ProblemType: Bug
DistroRelease: Ubuntu 19.10
Package: ubiquity 19.10.18
ProcVersionSignature: Ubuntu 5.3.0-17.18-generic 5.3.1
Uname: Linux 5.3.0-17-generic x86_64
NonfreeKernelModules: wl zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu8
Architecture: amd64
CasperVersion: 1.424
Date: Fri Oct 11 19:24:35 2019
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/xubuntu.seed quiet splash ---
LiveMediaBuild: Xubuntu 19.10 "Eoan Ermine" - Beta amd64 (20191011)
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)
Status changed to 'Confirmed' because the bug affects multiple users.