Ensure that the environment variables match what you need, or abort.

Changes for 0.009 - 2023-11-15T19:35:06+01:00

• Add App::FatPacker to deps.
• Add contributor gregor herrmann <gregoa@debian.org>
• Add Repology link to README.md.
• Available as a Debian package. (gregor herrmann <gregoa@debian.org>)