(Tvix developer here) 2 years after, Flakes are still what they are, IMHO, a pile of layering violations.
I do not see a path forward for them in Tvix before we get to fix them layer by layer, which Nix is trying to do (slowly?).
At some point, once we stabilize a bunch of things, I have some plans to do what I call the right design of Flakes, but it does not involve modifying completely the core of the interpreter to leak this implementation detail everywhere, but more make this a library concept.
I do not see a path forward for them in Tvix before we get to fix them layer by layer, which Nix is trying to do (slowly?).
At some point, once we stabilize a bunch of things, I have some plans to do what I call the right design of Flakes, but it does not involve modifying completely the core of the interpreter to leak this implementation detail everywhere, but more make this a library concept.