diff -r 8e0d823ef182 -r ae61851e6fe2 mercurial/configitems.py
--- a/mercurial/configitems.py	Tue Feb 28 00:01:41 2023 +0100
+++ b/mercurial/configitems.py	Tue Feb 28 15:25:47 2023 +0100
@@ -677,6 +677,22 @@
     b'serverrequirecert',
     default=False,
 )
+# Makes the status algorithm wait for the existence of this file
+# (or until a timeout of `devel.sync.status.pre-dirstate-write-file-timeout`
+# seconds) before taking the lock and writing the dirstate.
+# Status signals that it's ready to wait by creating a file
+# with the same name + `.waiting`.
+# Useful when testing race conditions.
+coreconfigitem(
+    b'devel',
+    b'sync.status.pre-dirstate-write-file',
+    default=None,
+)
+coreconfigitem(
+    b'devel',
+    b'sync.status.pre-dirstate-write-file-timeout',
+    default=2,
+)
 coreconfigitem(
     b'devel',
     b'strip-obsmarkers',