diff -r 2f1d6180737f -r 19533e4c3450 mercurial/cmdutil.py
--- a/mercurial/cmdutil.py	Wed Jan 15 15:47:03 2020 +0100
+++ b/mercurial/cmdutil.py	Thu Jan 16 12:17:03 2020 -0800
@@ -386,7 +386,7 @@
                 ui, originalhunks, recordfn, operation
             )
     except crecordmod.fallbackerror as e:
-        ui.warn(b'%s\n' % e.message)  # pytype: disable=attribute-error
+        ui.warn(b'%s\n' % e)
         ui.warn(_(b'falling back to text mode\n'))
 
     return patch.filterpatch(ui, originalhunks, match, operation)