grub-install failed on a XPS13 9350 UEFI dual boot with manual cryptsetup and lvm2

[Tanguy Herrmann]

I think I configured crytpsetup and lvm the same as would the installer do, but I didn't want lose the rest of the partition as the installer would do.

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: ubiquity 2.21.37
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-16-generic x86_64
ApportVersion: 2.19.1-0ubuntu3
Architecture: amd64
CasperVersion: 1.365
Date: Fri Nov 20 10:14:16 2015
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz.efi file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash ---
LiveMediaBuild: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
ProcEnviron:
 LANGUAGE=fr_FR.UTF-8
 PATH=(custom, no user)
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)