--- a/mercurial/repocache.py	Thu Feb 22 10:56:05 2024 +0100
+++ b/mercurial/repocache.py	Thu Feb 22 10:58:54 2024 +0100
@@ -119,7 +119,8 @@
     repo.obsstore.children
     for name in obsolete.cachefuncs:
         obsolete.getrevs(repo, name)
-    repo._phasecache.loadphaserevs(repo)
+    # ensure the phase cache is fully initialized
+    repo._phasecache.phase(repo, repo.changelog.tiprev())
 
 
 # TODO: think about proper API of attaching preloaded attributes