The Packages page should only be shown if Ubiquity is installed.

[Cubic PPA]

Currently, Cubic always shows the Packages page.

(1)
This page creates configurations used by the Ubiquity installer:
- filesystem.manifest-remove
- filesystem.manifest-minimal-remove

If Ubiquity is not installed, it does not make sense to show this page.

Ubiquity is not installed in Ubuntu server, other flavors of Ubuntu may not use Ubiquity, and the user may chose to uninstall Ubiquity. In these cases the Packages page should not be shown. Furthermore, if the user installs Ubiquity, the Packages page should be shown.

Therefore, Cubic should check if Ubiquity is installed in the custom OS to determine if the Packages page should be shown.

(2)
Additionally, Cubic checks for the existence of filesystem.manifest-minimal-remove to decide if the 2nd column on the Packages page (used to select packages to be removed for a minimal install) should be shown.

Older versions of Ubiquity (<18.04) only supported removing packages for a typical install. The minimal install option was introduced in Ubuntu Bionic Beaver 18.04.

The user may install a newer version of Ubiquity (>= 18.04) or revert to an older version, so Cubic should not depend on the existence of filesystem.manifest-minimal-remove in order to show the check boxes for a minimal install.

Therefore, Cubic should check the version of Ubiquity installed in the custom OS to determine if the minimal install check boxes should be shown on the Packages page. If Ubiquity >= 18.04, the minimal install check boxes should be visible.

[Cubic PPA (cubic-wizard)]

Fix released in version 2021.11-62.