diff -r f94d7e3e46a0 -r 08d02c1d7e67 mercurial/debugcommands.py
--- a/mercurial/debugcommands.py	Mon May 22 16:59:57 2017 +0200
+++ b/mercurial/debugcommands.py	Fri May 19 12:08:47 2017 +0200
@@ -1356,7 +1356,7 @@
                     parents = tuple(p.node() for p in parents)
                 repo.obsstore.create(tr, prec, succs, opts['flags'],
                                      parents=parents, date=date,
-                                     metadata=metadata)
+                                     metadata=metadata, ui=ui)
                 tr.close()
             except ValueError as exc:
                 raise error.Abort(_('bad obsmarker input: %s') % exc)