It amazes me how many people in that thread keep saying that we shouldn't even want it, that this is not what nix is about, that no one should install historical versions etc.
Given that my question never got an answer in HN (not until I had a discussion with the original article's author on Twitter and he posted this solution), it's clear that:
- this issue still exists
- how to do this is still not properly documented
- no one really knows how to do it in nix
- this extremely common functionality that is literally required for actual reproducible builds is entirely glossed over in all the articles praising nix
BTW, another issues linked is from 2015 https://github.com/NixOS/nixpkgs/issues/9682
Given that my question never got an answer in HN (not until I had a discussion with the original article's author on Twitter and he posted this solution), it's clear that:
- this issue still exists
- how to do this is still not properly documented
- no one really knows how to do it in nix
- this extremely common functionality that is literally required for actual reproducible builds is entirely glossed over in all the articles praising nix