--- a/rust/hg-cpython/src/dirstate/dirstate_map.rs	Thu Apr 08 14:58:44 2021 +0200
+++ b/rust/hg-cpython/src/dirstate/dirstate_map.rs	Tue Mar 30 09:56:04 2021 +0200
@@ -50,8 +50,12 @@
 py_class!(pub class DirstateMap |py| {
     @shared data inner: Box<dyn DirstateMapMethods + Send>;
 
-    def __new__(_cls, _root: PyObject) -> PyResult<Self> {
-        let inner = Box::new(RustDirstateMap::default());
+    def __new__(_cls, use_dirstate_tree: bool) -> PyResult<Self> {
+        let inner = if use_dirstate_tree {
+            Box::new(hg::dirstate_tree::dirstate_map::DirstateMap::new()) as _
+        } else {
+            Box::new(RustDirstateMap::default()) as _
+        };
         Self::create_instance(py, inner)
     }