def do_track(self, arg): """ track expression Display a graph showing which objects are referred by the value of the expression. This command requires pypy to be in the current PYTHONPATH. """ try: from rpython.translator.tool.reftracker import track except ImportError: print('** cannot import pypy.translator.tool.reftracker **', file=self.stdout) return try: val = self._getval(arg) except: pass else: track(val)