--- a/rust/hg-core/src/lib.rs	Tue May 14 22:56:58 2019 -0700
+++ b/rust/hg-core/src/lib.rs	Mon May 06 22:48:09 2019 +0200
@@ -2,6 +2,9 @@
 //
 // This software may be used and distributed according to the terms of the
 // GNU General Public License version 2 or any later version.
+extern crate byteorder;
+extern crate memchr;
+
 mod ancestors;
 pub mod dagops;
 pub use ancestors::{AncestorsIterator, LazyAncestors, MissingAncestors};
@@ -40,3 +43,29 @@
     ParentOutOfRange(Revision),
     WorkingDirectoryUnsupported,
 }
+
+#[derive(Clone, Debug, PartialEq)]
+pub enum DirstateParseError {
+    TooLittleData,
+    Overflow,
+    CorruptedEntry(String),
+}
+
+#[derive(Debug, PartialEq)]
+pub enum DirstatePackError {
+    CorruptedEntry(String),
+    CorruptedParent,
+    BadSize(usize, usize),
+}
+
+impl From<std::io::Error> for DirstatePackError {
+    fn from(e: std::io::Error) -> Self {
+        DirstatePackError::CorruptedEntry(e.to_string())
+    }
+}
+
+impl From<std::io::Error> for DirstateParseError {
+    fn from(e: std::io::Error) -> Self {
+        DirstateParseError::CorruptedEntry(e.to_string())
+    }
+}