--- a/tests/test-sparse-import.t	Tue Oct 06 21:06:18 2020 -0700
+++ b/tests/test-sparse-import.t	Thu Oct 08 15:35:44 2020 -0700
@@ -153,7 +153,7 @@
   > from mercurial import error, sparse
   > def extsetup(ui):
   >     def abort_refresh(*args, **kwargs):
-  >         raise error.Abort('sparse._refresh called!')
+  >         raise error.Abort(b'sparse._refresh called!')
   >     sparse.refreshwdir = abort_refresh
   > EOF
   $ cat >> $HGRCPATH <<EOF