Preparing A Build Environment
Getting BuildKit, or Go Ciel
You will need a clean environment for your packaging work. Packaging in a unclean, or even personally-used system environment demonstrates a lack of responsibility, and can result in packages with unrecorded dependencies, or other issues that could render a package unusable. A clean environment with minimal amount of libraries installed is the key to reproducible builds.
Ciel is an integrated, multi-instance, OverlayFS-based systemd container (nspawn) manager - providing functionalities for managing packaging environment(s). More importantly, Ciel can roll-back build environments to its original, clean state with a single command - this allows for an efficient way to ensure a minimal packaging environment.
Traditionally, packages are built in BuildKit, a base-installation of AOSC OS that provides additional development and packaging tools. Packagers will "spawn" package environments with
systemd-nspawn. After each packaging session, they are trusted to roll-back their environment manually in an expensive routine - that is, removing the whole system root, and extract a new one and configuring them again.
This method of packaging is now being phased out, and you are encouraged (and eventually required) to use Ciel instead.