diff --git a/mercurial/crecord.py b/mercurial/crecord.py
--- a/mercurial/crecord.py
+++ b/mercurial/crecord.py
@@ -547,7 +547,7 @@
     chunkselector = curseschunkselector(headerlist, ui, operation)
     if testfn and os.path.exists(testfn):
         testf = open(testfn)
-        testcommands = map(lambda x: x.rstrip('\n'), testf.readlines())
+        testcommands = [x.rstrip('\n') for x in testf.readlines()]
         testf.close()
         while True:
             if chunkselector.handlekeypressed(testcommands.pop(0), test=True):