4 ms·

I'm probably missing something, and please let me know if so and why, but it sounds like a chroot could solve path reproducibility.

soraminazuki 6y ago
Nix requires that each package only writes to a dedicated directory in /nix/store. For example, files for Firefox 33.1 package would go into /nix/store/b6gvzjyb2pg0kjfwrjmg1vfhh54ad73z-firefox-33.1. By not dumping files from every package in a common directory such as /usr, it requires each package to be explicit with its dependencies. This allows for many nice things explained elsewhere (e.g., https://nixos.org/nix/ https://nixos.org/nix/).
- cauthon 6y ago
  I still don't understand why that can't be solved by putting everything in /opt/nix/store
  - soraminazuki 6y ago
    You've got to keep it mind that Nix was designed as a system package manager and its primary target is NixOS. As such, I'd imagine that it wasn't all that unreasonable for Nix to assume ownership over /nix when the decision was made back then. Since Nix doesn't organize files according to FHS recommendations, it's never going to be FHS compliant. If so, what benefits would there be for Nix to choose /opt/nix over /nix? After all, /opt is where third-party packages reside and hardly the right choice anyways. The fact that Nix can be used as a third-party package manager outside of NixOS was a nice side-effect of its design choices. If Nix was designed from the start as a third-party package manager, it might have placed itself in /opt/nix. However, Nix was made years before some platforms started to lock down the root directory. It worked perfectly well with /nix before this happened. So instead of asking why Nix is placing itself in /nix instead of following some guidelines for traditional unix distributions, I think we should be asking why platforms are disallowing this. If a platform is going to make this big a breaking change, it'd better have a very good reason to do so. I fail to see the reason beside subjective aesthetics.

soraminazuki 6y ago

Nix requires that each package only writes to a dedicated directory in /nix/store. For example, files for Firefox 33.1 package would go into /nix/store/b6gvzjyb2pg0kjfwrjmg1vfhh54ad73z-firefox-33.1. By not dumping files from every package in a common directory such as /usr, it requires each package to be explicit with its dependencies. This allows for many nice things explained elsewhere (e.g., https://nixos.org/nix/ https://nixos.org/nix/).

cauthon 6y ago
I still don't understand why that can't be solved by putting everything in /opt/nix/store
- soraminazuki 6y ago
  You've got to keep it mind that Nix was designed as a system package manager and its primary target is NixOS. As such, I'd imagine that it wasn't all that unreasonable for Nix to assume ownership over /nix when the decision was made back then. Since Nix doesn't organize files according to FHS recommendations, it's never going to be FHS compliant. If so, what benefits would there be for Nix to choose /opt/nix over /nix? After all, /opt is where third-party packages reside and hardly the right choice anyways. The fact that Nix can be used as a third-party package manager outside of NixOS was a nice side-effect of its design choices. If Nix was designed from the start as a third-party package manager, it might have placed itself in /opt/nix. However, Nix was made years before some platforms started to lock down the root directory. It worked perfectly well with /nix before this happened. So instead of asking why Nix is placing itself in /nix instead of following some guidelines for traditional unix distributions, I think we should be asking why platforms are disallowing this. If a platform is going to make this big a breaking change, it'd better have a very good reason to do so. I fail to see the reason beside subjective aesthetics.