I may not have been precise enough here with the wording.
To clarify: Nixpkgs is a source distribution. You can see all of it here: https://github.com/NixOS/nixpkgs
From Nixpkgs, Hydra builds binary artifacts which then get distributed through the binary cache (cache.nixos.org). Users usually use binaries substituted by the cache but these binary artifacts are a direct result of the source, a small set of parameters (mainly platform), some time and some energy, so we usually rarely talk about them. They’re not interesting to us; we could reproduce them at any time by just building again.
What I’m talking about all happens at the “source” level, not the binary level. You obviously can’t take a Linux binary to a BSD and expect it to run but you can take a package definition initially made for Linux, try to build it on a BSD and run the result of that.
From experience with Darwin, this works in the majority of cases and usually only requires very few adjustments to the build recipe. With Nix, we have a full expression language at our hands, so we are able to to things like optionally adding some dependencies depending on the platform. We usually do not maintain separate build recipes for separate platforms; they usually use the same build definitions with different parameters.
OpenBSD is not trying to run the whole Nix distribution, they only tool the Nix package manager
What do you mean by this? OpenBSD “forking” Nix (a la Guix) would be news to me. Do you have some links for me?
Nix package manager on OpenBSD has no knowledge and no understanding of Linux or NixOS files.
The Nix package manager has no knowledge or understanding of “Linux or NixOS files” on any platform, including Linux/NixOS.
Its purpose is to know how to evaluate and realise Nix expressions.
I can evaluate a Nix expression for OpenBSD on my macOS machine. Nix doesn’t care.
(Obviously I can’t build it but I could theoretically cross-compile it, if support for that was to be wired up in Nixpkgs.)
I think you’re misunderstanding a bit how Nix and Nixpkgs work with different platforms.
I may not have been precise enough here with the wording.
To clarify: Nixpkgs is a source distribution. You can see all of it here: https://github.com/NixOS/nixpkgs
From Nixpkgs, Hydra builds binary artifacts which then get distributed through the binary cache (cache.nixos.org). Users usually use binaries substituted by the cache but these binary artifacts are a direct result of the source, a small set of parameters (mainly platform), some time and some energy, so we usually rarely talk about them. They’re not interesting to us; we could reproduce them at any time by just building again.
What I’m talking about all happens at the “source” level, not the binary level. You obviously can’t take a Linux binary to a BSD and expect it to run but you can take a package definition initially made for Linux, try to build it on a BSD and run the result of that.
From experience with Darwin, this works in the majority of cases and usually only requires very few adjustments to the build recipe. With Nix, we have a full expression language at our hands, so we are able to to things like optionally adding some dependencies depending on the platform. We usually do not maintain separate build recipes for separate platforms; they usually use the same build definitions with different parameters.
What do you mean by this? OpenBSD “forking” Nix (a la Guix) would be news to me. Do you have some links for me?
The Nix package manager has no knowledge or understanding of “Linux or NixOS files” on any platform, including Linux/NixOS.
Its purpose is to know how to evaluate and realise Nix expressions.
I can evaluate a Nix expression for OpenBSD on my macOS machine. Nix doesn’t care.
(Obviously I can’t build it but I could theoretically cross-compile it, if support for that was to be wired up in Nixpkgs.)
I think you’re misunderstanding a bit how Nix and Nixpkgs work with different platforms.
In the OpenBSD ports and packages tree for user installation here