Isn’t this an apples/oranges comparison.

Nix/NixOS is fundamentally about a declarative system configuration.

And as far as I understand, StageX doesn’t have that.

You can define an immutable, deterministic, and bootable system image for anything from an enclave to a laptop with just the primitives provided by the OCI Containerfile standard.

A stagex containerfile can define a system build recipe in such a way that several competing build systems that obey the same standard can all get the same hashes, which we sign every release.