anchor.diff:    inherit (lib)
       replaceChars;
   
  -  version = "2018-06-29";
  +  version = "2019-02-15";
     version' = replaceChars ["-"] [""] version;
   in
   stdenv.mkDerivation rec {
  
positive.code:     install generate/unix/bin*/iasl $out/bin
    '';
  
    meta = with lib; {
      description = "Intel ACPI Compiler";
      homepage = http://www.acpica.org/;
  
negative.code: 
    src = fetchurl {
      url = "https://acpica.org/sites/acpica/files/acpica-unix-${version'}.tar.gz";
      multihash = "QmaqR3MStuGyiYihahMBLA3Nsz3sBNQUwQvRhGAg4qHPTt";
      sha256 = "71133ab2b1b2e2f176a9b5081060571977a3d2c91b36722e198bffa7ce9b0d37";
    };
  
    nativeBuildInputs = [
  