failed to install during trial to sda3 where sda2 was non-uefi bootloader

[Jason Mitchell]

/dev/sda1 is an existing 16.04 non-eufi installation, while sda2 was the bootloader for it.

sda3 was a partition being formatted to be a new 17.10 installation, that was eufi, even though their was a warning saying that the non-eufi probably wouldn't be bootable.

It crashed out after stating it couldn't install the bootloader.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: ubiquity 17.10.10
ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4
Uname: Linux 4.13.0-16-generic x86_64
ApportVersion: 2.20.7-0ubuntu3
Architecture: amd64
CasperVersion: 1.387
Date: Sat Dec 16 09:44:35 2017
LiveMediaBuild: Lubuntu 17.10 "Artful Aardvark" - Release amd64 (20171017.1)
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Phillip Susi (psusi)]

Your disk is currently partitioned to boot in bios mode, but you booted the installer in EFI mode. A warning message prompted you that this could be a problem and recommended performing a bios mode install instead, but you chose not to. You either need to perform the bios mode install, or partition the disk using GPT and set up an EFI system partition to install in EFI mode. This will be done for you if you choose the "use entire disk" guided install option.