diff -r defabf63e969 -r 8ff1ecfadcd1 mercurial/utils/cborutil.py
--- a/mercurial/utils/cborutil.py	Tue Oct 08 15:15:37 2019 -0700
+++ b/mercurial/utils/cborutil.py	Tue Oct 08 15:06:18 2019 -0700
@@ -404,7 +404,7 @@
 
             if special != SPECIAL_START_ARRAY:
                 raise CBORDecodeError(
-                    b'expected array after finite set ' b'semantic tag'
+                    b'expected array after finite set semantic tag'
                 )
 
             return True, size, readcount + readcount2 + 1, SPECIAL_START_SET
@@ -746,7 +746,7 @@
                     SPECIAL_START_SET,
                 ):
                     raise CBORDecodeError(
-                        b'collections not supported as map ' b'keys'
+                        b'collections not supported as map keys'
                     )
 
                 # We do not allow special values to be used as map keys.
@@ -841,7 +841,7 @@
                     SPECIAL_START_SET,
                 ):
                     raise CBORDecodeError(
-                        b'collections not allowed as set ' b'values'
+                        b'collections not allowed as set values'
                     )
 
                 # We don't allow non-trivial types to exist as set values.