mention substituteAll in the trivial builders docs

[milahu]

substituteAll

https://discourse.nixos.org/t/how-pkgs-substituteall-chmod-x-buildenv/8167/2

Turns out pkgs.substituteAll has some extra functionality so pkgs.writeScript* isn’t needed even. So after some tinkering, this works:

let

  pkgs = import <nixpkgs> {};
  inherit (pkgs) lib;

  options = {
    foo = "foo";
    bar = "bar";
  };

  scripts = lib.mapAttrs (name: type: pkgs.substituteAll ({
    src = ./scripts + "/${name}";
    dir = "bin";
    isExecutable = true;
  } // options)) (builtins.readDir ./scripts);


  joined = pkgs.symlinkJoin {
    name = "scripts";
    paths = lib.attrValues scripts;
  };

in joined

simple example

cowsay-hello.nix

{ lib
, substituteAll
, runtimeShell
, cowsay
}:

substituteAll {
  name = "cowsay-hello";
  src = ./cowsay-hello.sh;
  dir = "bin";
  isExecutable = true;
  inherit runtimeShell;
  path = lib.makeBinPath [ cowsay ];
  postInstall = ''
    # ...
  '';
}

cowsay-hello.sh

#! @runtimeShell@

if [ -x "@runtimeShell@" ]; then export SHELL="@runtimeShell@"; fi;

export PATH=@path@:$PATH

exec cowsay hello

see also
nixpkgs/pkgs/os-specific/linux/nixos-rebuild/default.nix
nixpkgs/pkgs/os-specific/linux/nixos-rebuild/nixos-rebuild.sh
... and many other examples in nixpkgs

trivial builders docs

https://ryantm.github.io/nixpkgs/builders/trivial-builders/