--- a/rust/hg-core/src/dirstate_tree/dirstate_map.rs	Sun Jun 12 16:04:57 2022 +0100
+++ b/rust/hg-core/src/dirstate_tree/dirstate_map.rs	Wed May 18 09:50:39 2022 +0100
@@ -463,7 +463,7 @@
         if let Some(data) = on_disk.get(..data_size) {
             Ok(on_disk::read(data, metadata)?)
         } else {
-            Err(DirstateV2ParseError.into())
+            Err(DirstateV2ParseError::new("not enough bytes on disk").into())
         }
     }