diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -53,6 +53,8 @@ from .utils import (
     stringutil,
 )
 
+rustdirs = policy.importrust('dirstate', 'Dirs')
+
 base85 = policy.importmod(r'base85')
 osutil = policy.importmod(r'osutil')
 parsers = policy.importmod(r'parsers')
@@ -3204,6 +3206,9 @@ class dirs(object):
 if safehasattr(parsers, 'dirs'):
     dirs = parsers.dirs
 
+if rustdirs is not None:
+    dirs = rustdirs
+
 def finddirs(path):
     pos = path.rfind('/')
     while pos != -1:
diff --git a/rust/hg-core/src/dirstate/dirs_multiset.rs b/rust/hg-core/src/dirstate/dirs_multiset.rs
--- a/rust/hg-core/src/dirstate/dirs_multiset.rs
+++ b/rust/hg-core/src/dirstate/dirs_multiset.rs
@@ -118,7 +118,9 @@ impl DirsMultiset {
                     entry.remove();
                 }
                 Entry::Vacant(_) => {
-                    return Err(DirstateMapError::PathNotFound(path.to_owned()))
+                    return Err(DirstateMapError::PathNotFound(
+                        path.to_owned(),
+                    ))
                 }
             };