bug 1217051 - Pipe dump_syms stderr to /dev/null. r=catlee

            try:

                cmd = [self.dump_syms] + arch.split() + [file]

                self.output_pid(sys.stderr, ' '.join(cmd))

                proc = subprocess.Popen(cmd, stdout=subprocess.PIPE)

                proc = subprocess.Popen(cmd, stdout=subprocess.PIPE,

                                        stderr=open(os.devnull, 'wb'))

                module_line = proc.stdout.next()

                if module_line.startswith("MODULE"):

                    # MODULE os cpu guid debug_file