Civetman does have a lot of problems. If you spotted any errors, you can open an issue.
Civetman is built with Civet. The main file is here.
To start developing, you need to get pnpm installed (run corepack enable to install it). Then, run pnpm i to install the dependencies, then run pnpm dev to start developing.
The versions are managed with Changesets. See their official guide to learn how to use it.