diff -r 5c2e8a661418 -r 127d57e950e0 mercurial/debugcommands.py
--- a/mercurial/debugcommands.py	Wed Aug 07 20:09:53 2019 +0200
+++ b/mercurial/debugcommands.py	Wed Aug 07 20:10:08 2019 +0200
@@ -562,7 +562,7 @@
         raise error.CommandError('debugdata', _('invalid arguments'))
     r = cmdutil.openstorage(repo, 'debugdata', file_, opts)
     try:
-        ui.write(r.revision(r.lookup(rev), raw=True))
+        ui.write(r.rawdata(r.lookup(rev)))
     except KeyError:
         raise error.Abort(_('invalid revision identifier %s') % rev)