diff -r f0827211eb1f -r 2da4144e6716 mercurial/debugcommands.py
--- a/mercurial/debugcommands.py	Sat Jan 27 17:12:35 2018 +0900
+++ b/mercurial/debugcommands.py	Sat Jan 27 17:13:51 2018 +0900
@@ -2207,7 +2207,7 @@
     if not opts['show_revs']:
         return
     for c in revs:
-        ui.write("%s\n" % c)
+        ui.write("%d\n" % c)
 
 @command('debugsetparents', [], _('REV1 [REV2]'))
 def debugsetparents(ui, repo, rev1, rev2=None):