WIP: postprocessing pipeline

Now each run is executed in a independent folder

garlic/pp/result.nix

@@ -0,0 +1,43 @@
+{
+  stdenv
+, garlicTools
+, fetchExperiment
+}:
+
+{
+  trebuchetStage
+, experimentStage
+, garlicTemp
+}:
+
+with garlicTools;
+
+let
+  experimentName = baseNameOf (toString experimentStage);
+  fetcher = fetchExperiment {
+    sshHost = "mn1";
+    prefix = "/gpfs/projects/\\\$(id -gn)/\\\$(id -un)/garlic-out";
+    garlicTemp = "/tmp/garlic-temp";
+    inherit experimentStage trebuchetStage;
+  };
+in
+  stdenv.mkDerivation {
+    name = "result";
+    preferLocalBuild = true;
+    __noChroot = true;
+
+    phases = [ "installPhase" ];
+
+    installPhase = ''
+      expPath=${garlicTemp}/${experimentName}
+      if [ ! -e $expPath ]; then
+        echo "The experiment ${experimentName} is missing in ${garlicTemp}."
+        echo "Please fetch it and try again."
+        echo "You can execute ${trebuchetStage} to run the experiment."
+        echo "And then ${fetcher} to get the results."
+        exit 1
+      fi
+      mkdir -p $out
+      cp -a ${garlicTemp}/${experimentName} $out
+    '';
+  }