There's work happening in that direction: https://discourse.nixos.org/t/obsidian-systems-is-excited-to...

My impression is that although nix makes it easier to achieve repeatable builds, not all nix builds are repeatable. It takes some diligence on the part of the package author as well.

Switching nix from an inputs-addressed model to a content addressed one may shine a light on this, which will be nice for discovering the hidden variables which contribute to nondeterminism, but might come with its own headaches re: "why do I get a different hash than expected? Is it broken?"

I'm still excited to see it happen, but I think there's a certain crowd who might be disappointed that it's not as magical as they envisioned it.