diff -r 6b3b69b32a41 -r c6707e112d96 rust/hg-pyo3/src/exceptions.rs
--- a/rust/hg-pyo3/src/exceptions.rs	Wed Jan 29 13:49:29 2025 +0100
+++ b/rust/hg-pyo3/src/exceptions.rs	Wed Jan 29 14:03:24 2025 +0100
@@ -1,7 +1,9 @@
-use pyo3::exceptions::{PyRuntimeError, PyValueError};
+use pyo3::exceptions::{PyOSError, PyRuntimeError, PyValueError};
 use pyo3::import_exception;
 use pyo3::{create_exception, PyErr};
 
+use hg::dirstate::{on_disk::DirstateV2ParseError, DirstateError};
+
 use hg::revlog::nodemap::NodeMapError;
 use hg::UncheckedRevision;
 
@@ -85,3 +87,13 @@
     // in `hg::GraphError`. The C index always raises this simple ValueError.
     PyValueError::new_err("parent out of range")
 }
+
+#[allow(dead_code)]
+pub fn dirstate_error(err: DirstateError) -> PyErr {
+    PyOSError::new_err(format!("Dirstate error: {:?}", err))
+}
+
+#[allow(dead_code)]
+pub fn dirstate_v2_error(_err: DirstateV2ParseError) -> PyErr {
+    PyValueError::new_err("corrupted dirstate-v2")
+}