WIP: postprocessing pipeline

Now each run is executed in a independent folder

garlic/pp/hist/default.nix

@@ -0,0 +1,25 @@
+{
+  stdenv
+, ministat
+}:
+
+stdenv.mkDerivation {
+  name = "hist";
+  preferLocalBuild = true;
+  src = ./.;
+
+  dontBuild = true;
+  dontConfigure = true;
+
+  inherit ministat;
+
+  patchPhase = ''
+    substituteAllInPlace hist.sh 
+  '';
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp hist.sh $out/bin/hist
+    chmod +x $out/bin/hist
+  '';
+}