--- a/mercurial/error.py	Thu Oct 22 13:31:34 2020 -0700
+++ b/mercurial/error.py	Mon Oct 12 12:44:18 2020 -0700
@@ -188,6 +188,13 @@
     """
 
 
+class StateError(Abort):
+    """Indicates that the operation might work if retried in a different state.
+
+    Examples: Unresolved merge conflicts, unfinished operations.
+    """
+
+
 class HookLoadError(Abort):
     """raised when loading a hook fails, aborting an operation