It very much doesn't work like that. I work on Guix a little, and I remember someone saying ~5% of packages were broken at any given time. there is something of

It very much doesn't work like that. I work on Guix a little, and I remember someone saying ~5% of packages were broken at any given time. there is something of an equilibrium between packages breaking due to changes and someone fixing them. Packages are also not truly functional in the functional programming sense. For practical reasons, Nix/Guix just try their best to remove as much state as possible to make things behave consistently. But for example, the number of cores available is different between different machines and race conditions can occur.