diff -r 56df2ca5c032 -r ce566e0f73d0 mercurial/hg.py
--- a/mercurial/hg.py	Thu Apr 12 14:28:08 2018 +0530
+++ b/mercurial/hg.py	Thu Apr 12 14:30:37 2018 +0530
@@ -1021,7 +1021,7 @@
                         ret = (ctx.sub(subpath, allowcreate=False).verify()
                                or ret)
                     except error.RepoError as e:
-                        repo.ui.warn(('%s: %s\n') % (rev, e))
+                        repo.ui.warn(('%d: %s\n') % (rev, e))
             except Exception:
                 repo.ui.warn(_('.hgsubstate is corrupt in revision %s\n') %
                              node.short(ctx.node()))