diff -r 71a2c061865d -r 386737600689 mercurial/revset.py
--- a/mercurial/revset.py	Fri Mar 10 03:41:18 2023 +0100
+++ b/mercurial/revset.py	Wed Mar 08 11:00:30 2023 +0100
@@ -1967,6 +1967,12 @@
     return repo._phasecache.getrevset(repo, targets, subset)
 
 
+@predicate(b'_internal()', safe=True)
+def _internal(repo, subset, x):
+    getargs(x, 0, 0, _(b"_internal takes no arguments"))
+    return _phase(repo, subset, *phases.all_internal_phases)
+
+
 @predicate(b'_phase(idx)', safe=True)
 def phase(repo, subset, x):
     l = getargs(x, 1, 1, b"_phase requires one argument")