diff -r 72286f9e324f -r 2394cd58b81f hgext/rebase.py
--- a/hgext/rebase.py	Thu Jun 28 22:23:08 2018 -0400
+++ b/hgext/rebase.py	Thu Jun 28 21:24:47 2018 +0530
@@ -820,7 +820,7 @@
     if dryrun:
         leaveunfinished = True
         inmemory = True
-        rbsrt = rebaseruntime(repo, ui, inmemory, opts)
+        rbsrt = rebaseruntime(repo, ui, inmemory, pycompat.byteskwargs(opts))
         try:
             overrides = {('rebase', 'singletransaction'): True}
             with ui.configoverride(overrides, 'rebase'):