diff -r 5cc5a5561c3f -r afa884015e66 mercurial/exchangev2.py
--- a/mercurial/exchangev2.py	Thu Jan 10 15:57:13 2019 +0100
+++ b/mercurial/exchangev2.py	Thu Jan 10 16:03:07 2019 +0100
@@ -98,7 +98,7 @@
         relevantcsetnodes = set()
         clnode = repo.changelog.node
 
-        for rev in repo.revs(b'ancestors(%ln, %d)',
+        for rev in repo.revs(b'ancestors(%ln, %s)',
                              pullheads, pullop.depth - 1):
             relevantcsetnodes.add(clnode(rev))