def start(self):
        """ Start capturing on targetfd using memorized tmpfile. """
        try:
            os.fstat(self.targetfd_save)
        except (AttributeError, __HOLE__):
            raise ValueError("saved filedescriptor not valid anymore")
        os.dup2(self.tmpfile_fd, self.targetfd)
        self.syscapture.start()
dataset/ETHPy150Open pytest-dev/pytest/_pytest/capture.py/FDCapture.start