diff --git a/Cargo.toml b/Cargo.toml
index 833abf0..ddc5c2d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -55,6 +55,7 @@ enum_dispatch = "0.3"
 geo.workspace = true
 log.workspace = true
 petgraph.workspace = true
+ron = "0.10"
 rstar.workspace = true
 serde.workspace = true
 spade.workspace = true
diff --git a/crates/planar-incr-embed/src/navmesh/mod.rs b/crates/planar-incr-embed/src/navmesh/mod.rs
index 0b68664..dc45eb5 100644
--- a/crates/planar-incr-embed/src/navmesh/mod.rs
+++ b/crates/planar-incr-embed/src/navmesh/mod.rs
@@ -393,6 +393,14 @@ impl<'a, B: NavmeshBase + 'a> NavmeshRefMut<'a, B> {
 }
 
 impl<'a, B: NavmeshBase + 'a> NavmeshRef<'a, B> {
+    pub fn to_owned(&self) -> Navmesh<B> {
+        Navmesh {
+            nodes: Arc::new(self.nodes.clone()),
+            edges: Arc::new(self.edges.clone()),
+            edge_paths: self.edge_paths.to_vec().into_boxed_slice(),
+        }
+    }
+
     #[inline(always)]
     pub fn resolve_edge_data(
         &self,
diff --git a/src/autorouter/execution.rs b/src/autorouter/execution.rs
index f997a4d..22a601d 100644
--- a/src/autorouter/execution.rs
+++ b/src/autorouter/execution.rs
@@ -86,6 +86,19 @@ impl<M: AccessMesadata + Clone> ExecutionStepper<M> {
                                 .board
                                 .try_set_band_between_nodes(source, target, *band);
                         }
+
+                        let topo_navmesh = autoroute.maybe_topo_navmesh().unwrap().to_owned();
+                        let mut pretty_config = ron::ser::PrettyConfig::new();
+                        pretty_config.depth_limit = 2;
+                        log::debug!(
+                            "topo navmesh result: {}",
+                            ron::ser::to_string_pretty(
+                                &ng::pie::navmesh::NavmeshSer::from(topo_navmesh),
+                                pretty_config
+                            )
+                            .unwrap()
+                        );
+
                         ControlFlow::Break((
                             Some(autoroute.last_recorder.clone()),
                             "finished topo-autorouting".to_string(),
diff --git a/src/router/ng/mod.rs b/src/router/ng/mod.rs
index fd6734d..00091fa 100644
--- a/src/router/ng/mod.rs
+++ b/src/router/ng/mod.rs
@@ -50,7 +50,9 @@ pub use router::*;
 #[derive(Clone, Copy, Debug)]
 pub struct PieNavmeshBase;
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(
+    Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, serde::Deserialize, serde::Serialize,
+)]
 pub struct EtchedPath {
     pub end_points: EdgeIndex<FixedDotIndex>,
 }
diff --git a/src/router/ng/poly.rs b/src/router/ng/poly.rs
index 89bfa07..b636b7c 100644
--- a/src/router/ng/poly.rs
+++ b/src/router/ng/poly.rs
@@ -202,6 +202,11 @@ impl PolygonRouting {
                 break;
             }
         }
+        log::debug!(
+            "route_to_exit on {:?} finished, head = {:?}",
+            self.apex,
+            active_head,
+        );
         Ok((active_head, route_length))
     }
 }