partitioner does not warn when missing bios_grub partition

[Robin]

I believe that installation falied, fatal error: failed to install grub, because a small grub_bios partition is necessary on a GPT partitioned disk. The install was using manual partition (to support a certain use scheme), but the installer did not notice this at the partition selection step.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: ubiquity 2.18.7
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
CasperVersion: 1.340
Date: Sun Jan 11 12:52:14 2015
InstallCmdLine: file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash -- maybe-ubiquity
LiveMediaBuild: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
ProcEnviron:
 LANGUAGE=en_GB.UTF-8
 TERM=linux
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_GB.UTF-8
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)

[Phillip Susi (psusi)]

I'd noticed this myself not too long ago. It seems that the check.d/biosgrub script skips the warning if *any* disk is using MBR instead of GPT, and this test typically sees the MBR partition table on the usb stick being used to install from.