anchor.diff:            url = "https://github.com/purescript/purescript-tailrec.git";
             rev = "69f4625969e313203028968e4a9f743fa7f87883";
             sha256 = "0z7k80nl8dgv8mc2w8xsl2n0637bd1l8ppxak8kaifgjjwa81hx3";
  +        };
  +        phases = "installPhase";
  +        installPhase = "ln -s $src $out";
  +      };
  +
  +    "test-unit" = pkgs.stdenv.mkDerivation {
  +        name = "test-unit";
  +        version = "v15.0.0";
  +        src = pkgs.fetchgit {
  +          url = "https://github.com/bodil/purescript-test-unit.git";
  +          rev = "351c55b632e0c0ebffae05837909995a03de3406";
  +          sha256 = "06lb90vppa7naqqwz7wbvlkkyz86pbdd3ycw3d2iygvxbzkz8xjn";
           };
           phases = "installPhase";
           installPhase = "ln -s $src $out";
  
positive.code:         installPhase = "ln -s $src $out";
        };
  
      "filterable" = pkgs.stdenv.mkDerivation {
          name = "filterable";
          version = "v3.0.1";
  
negative.code:         installPhase = "ln -s $src $out";
        };
  
      "generics-rep" = pkgs.stdenv.mkDerivation {
          name = "generics-rep";
          version = "v6.1.1";
          src = pkgs.fetchgit {
            url = "https://github.com/purescript/purescript-generics-rep.git";
            rev = "aae27ba1de21dda342dcdfc8b3cc5b951bd5b3ec";
            sha256 = "15vchzbcvf6byks90q14lvcwb8hnxqzm2mrlxi7v1f7has4s74kn";
          };
          phases = "installPhase";
          installPhase = "ln -s $src $out";
        };
  
      "globals" = pkgs.stdenv.mkDerivation {
          name = "globals";
          version = "v4.0.0";
  