diff -r 5e64c93d5f94 -r d57386e5c80e rust/hg-cpython/src/revlog.rs
--- a/rust/hg-cpython/src/revlog.rs	Sat May 01 14:47:39 2021 +0200
+++ b/rust/hg-cpython/src/revlog.rs	Thu Apr 01 11:31:54 2021 +0200
@@ -177,6 +177,11 @@
         self.call_cindex(py, "entry_binary", args, kw)
     }
 
+    /// return a binary packed version of the header
+    def pack_header(&self, *args, **kw) -> PyResult<PyObject> {
+        self.call_cindex(py, "pack_header", args, kw)
+    }
+
     /// get an index entry
     def get(&self, *args, **kw) -> PyResult<PyObject> {
         self.call_cindex(py, "get", args, kw)