Fallout in public-facing and semi-public-facing libs

src/libgraphviz/lib.rs

@@ -524,7 +524,7 @@ pub trait GraphWalk<'a, N, E> {
     fn target(&'a self, edge: &E) -> N;
 }
 
-#[derive(Copy, PartialEq, Eq, Debug)]
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
 pub enum RenderOption {
     NoEdgeLabels,
     NoNodeLabels,