even better graphviz
diff --git a/Gopkg.lock b/Gopkg.lock
index f478101..977c48a 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -346,6 +346,14 @@
   revision = "5420a8b6744d3b0345ab293f6fcba19c978f1183"
   version = "v2.2.1"
 
+[[projects]]
+  branch = "master"
+  digest = "1:9132eacc44d9bd1e03145ea2e9d4888800da7773d6edebb401f8cd34c9fb8380"
+  name = "vbom.ml/util"
+  packages = ["sortorder"]
+  pruneopts = "UT"
+  revision = "efcd4e0f97874370259c7d93e12aad57911dea81"
+
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
@@ -360,6 +368,7 @@
     "github.com/q3k/statusz",
     "golang.org/x/net/context",
     "google.golang.org/grpc",
+    "vbom.ml/util/sortorder",
   ]
   solver-name = "gps-cdcl"
   solver-version = 1