(nlohmann_json.override { multipleHeaders = true; })
, nixpkgs ? builtins.fetchTarball https://github.com/NixOS/nixpkgs/archive/release-19.09.tar.gz
      NIX_LDFLAGS = [ "-lpthread" ];

            auto v = findAlongAttrPath(state, attrPath, autoArgs, *vRoot).first;

            auto vTmp = findAlongAttrPath(state, attrPath, autoArgs, *vRoot).first;

            state.forceValue(*v);

            auto v = state.allocValue();
            state.autoCallFunction(autoArgs, *vTmp, *v);

            else if (v->type == tNull)
                ;
            else throw TypeError("attribute '%s' is %s, which is not supported", attrPath, showType(*v));

    my ($nixExprPath, $nixExprInput);
    my $flake;
    if ($type == 0) {
        ($nixExprPath, $nixExprInput) = nixExprPathFromParams $c;
    } elsif ($type == 1) {
        $flake = trim($c->stash->{params}->{"flakeref"});
        error($c, "Invalid flake URI ‘$flake’.") if $flake !~ /^[a-zA-Z]/;
    } else {
        error($c, "Invalid jobset type.");
    }

    my ($value) = @_;
    return $value;

    my ($input) = @_;
    return
        "{ outPath = builtins.storePath " . $input->{storePath} . "" .
        "; inputType = \"" . $input->{type} . "\"" .
        (defined $input->{uri} ? "; uri = \"" . $input->{uri} . "\"" : "") .
        (defined $input->{revNumber} ? "; rev = " . $input->{revNumber} . "" : "") .
        (defined $input->{revision} ? "; rev = \"" . $input->{revision} . "\"" : "") .
        (defined $input->{revCount} ? "; revCount = " . $input->{revCount} . "" : "") .
        (defined $input->{gitTag} ? "; gitTag = \"" . $input->{gitTag} . "\"" : "") .
        (defined $input->{shortRev} ? "; shortRev = \"" . $input->{shortRev} . "\"" : "") .
        (defined $input->{version} ? "; version = \"" . $input->{version} . "\"" : "") .
        (defined $input->{outputName} ? "; outputName = \"" . $input->{outputName} . "\"" : "") .
        (defined $input->{drvPath} ? "; drvPath = builtins.storePath " . $input->{drvPath} . "" : "") .
        ";}";

    my ($inputInfo) = @_;

            push @res, "--arg", $input, booleanToString($alt->{value});

            push @res, "--arg", $input, buildInputToString($alt);

    my ($inputInfo, $nixExprInputName, $nixExprPath) = @_;

    my @cmd = ("hydra-eval-jobs",
               inputsToArgs($inputInfo));

    die "hydra-eval-jobs returned " . ($res & 127 ? "signal $res" : "exit code " . ($res >> 8))

    my @args = ($jobset->nixexprinput, $jobset->nixexprpath, inputsToArgs($inputInfo));

    my ($jobs, $nixExprInput) = evalJobs($inputInfo, $jobset->nixexprinput, $jobset->nixexprpath);

                foreach my $drvPath (@{$job->{constituents}}) {