diff -r 112ba1c7d65d -r 75e93d95aae6 mercurial/debugcommands.py
--- a/mercurial/debugcommands.py	Sat May 06 12:02:31 2017 -0700
+++ b/mercurial/debugcommands.py	Sat May 06 12:12:53 2017 -0700
@@ -1707,9 +1707,9 @@
                 numother += 1
 
         # Obtain data on the raw chunks in the revlog.
-        chunk = r._chunkraw(rev, rev)[1]
-        if chunk:
-            chunktype = chunk[0]
+        segment = r._getsegmentforrevs(rev, rev)[1]
+        if segment:
+            chunktype = segment[0]
         else:
             chunktype = 'empty'