--- a/mercurial/statprof.py	Sun Oct 01 12:21:50 2017 +0100
+++ b/mercurial/statprof.py	Thu Dec 14 20:18:15 2017 +0000
@@ -815,7 +815,6 @@
         tos = sample.stack[0]
         name = tos.function
         path = simplifypath(tos.path)
-        category = '%s:%d' % (path, tos.lineno)
         stack = tuple((('%s:%d' % (simplifypath(frame.path), frame.lineno),
                         frame.function) for frame in sample.stack))
         qstack = collections.deque(stack)