cross-posted from: https://lemmy.ml/post/3796605

Note that once solved, the code from this bounty will be made publicly available for anybody who wants to use it on their ubuntu installer. Please see link for full details including results of previous attempts to fix the issue.

Bounty Amount and Terms:

This bounty is for $250 USD and will be paid out via PayPal. This bounty amount will increase at random amounts and intervals until it is claimed. The bounty is open to residents of all countries except those under embargo or sanction by the US govt. The bounty will be paid out to the first person to produce a working preseed recipe or steps to achieve the desired result. When the bounty is successfully claimed, this post will be updated. By submitting your fix and claiming your bounty, you agree to release any code, preseed files, etc delivered to us into the public domain and surrender all rights you hold to them.

Problem:

We want to create an Xubuntu 22.04 ISO using Cubic. Using the preseed, we want to automatically partition the drive with a standard encrypted LVM setup (same one that is achieved manually via the GUI installer). Unfortunately, all existing recipes, which supposedly worked in prior Ubuntu versions, fail with the error No modifications can be made to the device: Encrypted Volume (sda1p2_crypt) for the following reasons: In use by LVM module group crypt or whatever the volume is titled in the partman recipe.

Desired Solution:

A preseed file which enables automatic encrypted LVM partitioning identical to what is achieved by choosing it manually in the GUI installer

This solution must be compatible with Cubic and may involve making modifications to the underlying iso, for example, by issuing commands at the chroot terminal provided by Cubic. It should not require any modifications to the ISO outside of the abilities provided by Cubic.