diff -r 426cf9d98a5d -r 07a7b57d3e33 mercurial/formatter.py
--- a/mercurial/formatter.py	Mon Feb 21 10:25:53 2022 -0700
+++ b/mercurial/formatter.py	Mon Feb 21 10:26:25 2022 -0700
@@ -558,8 +558,7 @@
 
 
 def literal_templatespec(tmpl):
-    if pycompat.ispy3:
-        assert not isinstance(tmpl, str), b'tmpl must not be a str'
+    assert not isinstance(tmpl, str), b'tmpl must not be a str'
     return templatespec(b'', tmpl, None)