diff --git a/mercurial/pure/parsers.py b/mercurial/pure/parsers.py
--- a/mercurial/pure/parsers.py
+++ b/mercurial/pure/parsers.py
@@ -36,7 +36,7 @@ def parse_index2(data, inline):
     s = struct.calcsize(indexformatng)
     index = []
     cache = None
-    n = off = 0
+    off = 0
 
     l = len(data) - s
     append = index.append
@@ -45,7 +45,6 @@ def parse_index2(data, inline):
         while off <= l:
             e = _unpack(indexformatng, data[off:off + s])
             append(e)
-            n += 1
             if e[1] < 0:
                 break
             off += e[1] + s
@@ -53,7 +52,6 @@ def parse_index2(data, inline):
         while off <= l:
             e = _unpack(indexformatng, data[off:off + s])
             append(e)
-            n += 1
             off += s
 
     if off != len(data):