Ubiquity can not be used from an installed system ( non casper ) to install to another drive

[Alberto Salvia Novella]

STEPS TO REPRODUCE:
1. On an installed system, install the "ubiquity-frontend-gtk" package.
2. Connect an external USB drive.
3. Using the "Install RELEASE" application, try to install Ubuntu into the drive.

RESULT:
- The installation crashes.

RELEVANT INFORMATION:
- The usefulness of this process is being able to create writable USB drives easily, which is very valuable when testing Ubuntu releases on bare metal.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubiquity 2.21.63.3
ProcVersionSignature: Ubuntu 4.4.0-75.96-generic 4.4.59
Uname: Linux 4.4.0-75-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
Date: Mon May 1 01:08:56 2017
InstallCmdLine: file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash --- maybe-ubiquity
InstallationDate: Installed on 2016-05-02 (363 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
JournalErrors:
 Error: command ['journalctl', '-b', '--priority=warning', '--lines=1000'] failed with exit code 1: Hint: You are currently not seeing messages from other users and the system.
       Users in the 'systemd-journal' group can see all messages. Pass -q to
       turn off this notice.
 No journal files were opened due to insufficient permissions.
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. We noticed that you were installing the LTS version of Ubuntu using an older version of the installation media. The latest point release of 16.04 is 16.04.2. Please try installing from that version of the installation media and see if that resolves your issue. Thanks in advance!

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Alberto Salvia Novella (es20490446e)]

Tried using an updated LTS system.

[Phillip Susi (psusi)]

I'm pretty sure that is simply not a supported use case for ubiquity, but I'll leave it to more active developers to decide if this should be a wontfix or just leave it as a new feature request.