Installing on manually prepared LUKS+LVM+EXT4 volume

[Laurent Richer]

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 238.5G 0 disk
├─sda1 8:1 0 100M 0 part /target/boot/efi
├─sda2 8:2 0 900M 0 part
├─sda3 8:3 0 128M 0 part
├─sda4 8:4 0 95.4G 0 part
├─sda5 8:5 0 122G 0 part
│ └─sda5_crypt 252:0 0 122G 0 crypt
│ ├─zenbook-swap 252:1 0 7.5G 0 lvm [SWAP]
│ ├─zenbook-root 252:2 0 7.5G 0 lvm /target
│ ├─zenbook-var 252:3 0 7.5G 0 lvm /target/var
│ └─zenbook-home 252:4 0 59.6G 0 lvm /target/home
└─sda6 8:6 0 20G 0 part
sdb 8:16 1 3.8G 0 disk
└─sdb1 8:17 1 3.8G 0 part /cdrom
loop0 7:0 0 1.1G 1 loop /rofs

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: ubiquity 2.19.8
ProcVersionSignature: Ubuntu 3.16.0-17.23-generic 3.16.3
Uname: Linux 3.16.0-17-generic x86_64
ApportVersion: 2.14.7-0ubuntu2
Architecture: amd64
CasperVersion: 1.344
Date: Tue Oct 7 13:39:28 2014
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz.efi file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash --
LiveMediaBuild: Ubuntu 14.10 "Utopic Unicorn" - Alpha amd64 (20140923)
ProcEnviron:
 LANGUAGE=en_CA.UTF-8
 PATH=(custom, no user)
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)