Implemented PEP 405 (Python virtual environments).
diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index 2606607..8161b94 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -564,7 +564,7 @@
         random.shuffle(selected)
     if trace:
         import trace, tempfile
-        tracer = trace.Trace(ignoredirs=[sys.prefix, sys.exec_prefix,
+        tracer = trace.Trace(ignoredirs=[sys.base_prefix, sys.base_exec_prefix,
                                          tempfile.gettempdir()],
                              trace=False, count=True)