diff -r 6bdea0efdab5 -r 46f4d71ed505 mercurial/sshpeer.py
--- a/mercurial/sshpeer.py	Sat Mar 10 12:22:08 2018 -0500
+++ b/mercurial/sshpeer.py	Sat Mar 10 12:45:10 2018 -0500
@@ -32,10 +32,11 @@
     """display all data currently available on pipe as remote output.
 
     This is non blocking."""
-    s = util.readpipe(pipe)
-    if s:
-        for l in s.splitlines():
-            ui.status(_("remote: "), l, '\n')
+    if pipe:
+        s = util.readpipe(pipe)
+        if s:
+            for l in s.splitlines():
+                ui.status(_("remote: "), l, '\n')
 
 class doublepipe(object):
     """Operate a side-channel pipe in addition of a main one