Guix doesn't really share any of the codebase with Nix. Guix uses a modified version of the Nix daemon, but that is a tiny fraction of the total source code.

Guix doesn't really share any of the codebase with Nix. Guix uses a modified version of the Nix daemon, but that is a tiny fraction of the total source code. Guix is an alternative implementation of the packaging model pioneered by Nix, plus additional features not found in Nix.