Backport 52621:
Bug #1588287: fix invalid assertion for `1,2` in debug builds.
diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
index c39e416..76483f6 100644
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -709,6 +709,7 @@
 
 x = `x`
 x = `1 or 2 or 3`
+x = `1,2`
 x = x
 x = 'x'
 x = 123