--- a/regression.py	Tue Apr 21 12:32:05 2009 +0200
+++ b/regression.py	Tue Apr 21 12:32:55 2009 +0200
@@ -159,7 +159,7 @@
             script = os.path.abspath(os.path.join('..', *os.path.split(program)))
             argv = [self.env['PYTHON'], script] + arguments
             try:
-                wutils.run_argv(argv, self.env, cwd=trace_output_path)
+                wutils.run_argv(argv, self.env, cwd=trace_output_path, force_no_valgrind=True)
             except Utils.WafError, ex:
                 print >> sys.stderr, ex
                 return 1
@@ -191,7 +191,7 @@
             script = os.path.abspath(os.path.join('..', *os.path.split(program)))
             argv = [self.env['PYTHON'], script] + arguments
             try:
-                retval = wutils.run_argv(argv, self.env, cwd=trace_output_path)
+                retval = wutils.run_argv(argv, self.env, cwd=trace_output_path, force_no_valgrind=True)
             except Utils.WafError, ex:
                 print >> sys.stderr, ex
                 return 1

--- a/wscript	Tue Apr 21 12:32:05 2009 +0200
+++ b/wscript	Tue Apr 21 12:32:55 2009 +0200
@@ -253,9 +253,10 @@
             env.append_value("LINKFLAGS", "-Wl,--enable-auto-import")
         cxx, = env['CXX']
         p = subprocess.Popen([cxx, '-print-file-name=libstdc++.so'], stdout=subprocess.PIPE)
-        libstdcxx = p.stdout.read().strip()
+        libstdcxx_location = os.path.dirname(p.stdout.read().strip())
         p.wait()
-        conf.env.append_value('NS3_MODULE_PATH', os.path.dirname(libstdcxx))
+        if libstdcxx_location:
+            conf.env.append_value('NS3_MODULE_PATH', libstdcxx_location)
 
     conf.sub_config('src')
     conf.sub_config('utils')
@@ -524,7 +525,8 @@
 
     if env['ENABLE_PYTHON_BINDINGS']:
         print "-- Running NS-3 Python bindings unit tests..."
-        wutils.run_argv([env['PYTHON'], os.path.join("utils", "python-unit-tests.py")], env, proc_env)
+        wutils.run_argv([env['PYTHON'], os.path.join("utils", "python-unit-tests.py")],
+                        env, proc_env, force_no_valgrind=True)
     else:
         print "-- Skipping NS-3 Python bindings unit tests: Python bindings not enabled."
 

--- a/wutils.py	Tue Apr 21 12:32:05 2009 +0200
+++ b/wutils.py	Tue Apr 21 12:32:55 2009 +0200
@@ -114,9 +114,9 @@
 
     return proc_env
 
-def run_argv(argv, env, os_env=None, cwd=None):
+def run_argv(argv, env, os_env=None, cwd=None, force_no_valgrind=False):
     proc_env = get_proc_env(os_env)
-    if Options.options.valgrind:
+    if Options.options.valgrind and not force_no_valgrind:
         if Options.options.command_template:
             raise Utils.WafError("Options --command-template and --valgrind are conflicting")
         if not env['VALGRIND']: