Nix pill 10

autotools.nix

pkgs: attrs:
  with pkgs;
  let defaultAttrs = {
    builder = "${bash}/bin/bash";
    args = [ ./builder.sh ];
    setup = ./setup.sh;
    baseInputs = [ gnutar gzip gnumake gcc binutils coreutils gawk gnused gnugrep patchelf findutils ];
    buildInputs = [];
    system = builtins.currentSystem;
  };
  in
  derivation (defaultAttrs // attrs)

builder.sh

set -e
source $setup
genericBuild

hello.nix

let
  pkgs = import <nixpkgs> {};
  mkDerivation = import ./autotools.nix pkgs;
in mkDerivation {
  name = "hello";
  src = ./hello-2.9.tar.gz;
}

setup.sh

unset PATH
for p in $baseInputs $buildInputs; do
  export PATH=$p/bin${PATH:+:}$PATH
done

function unpackPhase() {
  tar -xzf $src

  for d in *; do
    if [ -d "$d" ]; then
      cd "$d"
      break
    fi
  done
}

function configurePhase() {
  ./configure --prefix=$out
}

function buildPhase() {
  make
}

function installPhase() {
  make install
}

function fixupPhase() {
  find $out -type f -exec patchelf --shrink-rpath '{}' \; -exec strip '{}' \; 2>/dev/null
}

function genericBuild() {
  unpackPhase
  configurePhase
  buildPhase
  installPhase
  fixupPhase
}

I got the error message /bin/bash: ar: command not found. I fixed this by changing binutils to binutils-unwrapped at line 7 in autotools.nix.