code: def _get_bin_dir(self):
          
          for subdir in ("bin", "Scripts"):
              bin_dir = os.path.join(self.abs_home_dir, subdir)
              if os.path.isdir(bin_dir):
                  print("bin dir: %r" % bin_dir)
                  return bin_dir
          raise RuntimeError("Can't find 'bin/Scripts' dir in: %r" % self.abs_home_dir)
docs: Normaly we have a ...env/bin/ dir.
          But under Windows we have ...env/Scripts/
          But not PyPy2 under Windows, see:
          https://bitbucket.org/pypy/pypy/issues/2125/tcl-doesnt-work-inside-a-virtualenv-on#comment-21247266
  
          So just try to test via os.path.isdir()