--- a/contrib/perf-utils/subsetmaker.py	Tue Jul 20 15:07:10 2021 +0200
+++ b/contrib/perf-utils/subsetmaker.py	Sun Mar 13 15:53:29 2022 +0100
@@ -102,7 +102,9 @@
     for x in range(n):
         if not heads:
             break
-        pick = rand.choice(list(heads))
+        pickable = list(heads)
+        pickable.sort()
+        pick = rand.choice(pickable)
         heads.remove(pick)
         assert pick not in selected
         selected.add(pick)