diff --git a/mercurial/error.py b/mercurial/error.py
--- a/mercurial/error.py
+++ b/mercurial/error.py
@@ -51,8 +51,8 @@
         super(Hint, self).__init__(*args, **kw)
 
 
-class Abort(Hint, Exception):
-    """Raised if a command needs to print an error and exit."""
+class Error(Hint, Exception):
+    """Base class for Mercurial errors."""
 
     def __init__(
         self, message, hint=None, coarse_exit_code=None, detailed_exit_code=None
@@ -87,6 +87,10 @@
         return message
 
 
+class Abort(Error):
+    """Raised if a command needs to print an error and exit."""
+
+
 class StorageError(Hint, Exception):
     """Raised when an error occurs in a storage layer.