diff -r 61134a232d00 -r 8859de3e83dc mercurial/revset.py
--- a/mercurial/revset.py	Thu Apr 02 16:02:21 2020 -0400
+++ b/mercurial/revset.py	Fri Apr 10 22:22:09 2020 +0800
@@ -281,7 +281,7 @@
     return ancdepths, descdepths
 
 
-def generationsrel(repo, subset, x, rel, z, order):
+def generationssubrel(repo, subset, x, rel, z, order):
     # TODO: rewrite tests, and drop startdepth argument from ancestors() and
     # descendants() predicates
     a, b = getintrange(
@@ -2650,8 +2650,8 @@
 }
 
 subscriptrelations = {
-    b"g": generationsrel,
-    b"generations": generationsrel,
+    b"g": generationssubrel,
+    b"generations": generationssubrel,
 }