diff -r da459d426c20 -r dd6bc2509bdc mercurial/debugcommands.py
--- a/mercurial/debugcommands.py	Mon Aug 20 23:06:47 2018 +0000
+++ b/mercurial/debugcommands.py	Mon Aug 20 23:08:57 2018 +0000
@@ -556,7 +556,7 @@
         file_, rev = None, file_
     elif rev is None:
         raise error.CommandError('debugdata', _('invalid arguments'))
-    r = cmdutil.openrevlog(repo, 'debugdata', file_, opts)
+    r = cmdutil.openstorage(repo, 'debugdata', file_, opts)
     try:
         ui.write(r.revision(r.lookup(rev), raw=True))
     except KeyError: