--- a/mercurial/error.py	Tue Oct 06 21:52:27 2020 -0700
+++ b/mercurial/error.py	Tue Oct 06 20:37:35 2020 -0700
@@ -100,6 +100,11 @@
 class CommandError(Exception):
     """Exception raised on errors in parsing the command line."""
 
+    def __init__(self, command, message):
+        self.command = command
+        self.message = message
+        super(CommandError, self).__init__()
+
     __bytes__ = _tobytes