error

C:\Users\r.prado\Desktop\PySide-1.2.0>python setup.py bdist_wininst --qmake=C:\Q
t\Qt5.1.1\5.1.1\msvc2012_64_opengl\bin\qmake.exe --openssl=C:\OpenSSL-Win32\bin
Removing C:\Users\r.prado\Desktop\PySide-1.2.0\pyside_package
running bdist_wininst
running build
Python architecture is 32bit
Searching vcvarsall.bat
Traceback (most recent call last):
  File "setup.py", line 955, in <module>
    ext_package = 'PySide',
  File "C:\Python27\lib\distutils\core.py", line 152, in setup
    dist.run_commands()
  File "C:\Python27\lib\distutils\dist.py", line 953, in run_commands
    self.run_command(cmd)
  File "C:\Python27\lib\distutils\dist.py", line 972, in run_command
    cmd_obj.run()
  File "build\bdist.win32\egg\setuptools\command\bdist_wininst.py", line 36, in
run
  File "C:\Python27\lib\distutils\command\bdist_wininst.py", line 131, in run
    self.run_command('build')
  File "C:\Python27\lib\distutils\cmd.py", line 326, in run_command
    self.distribution.run_command(command)
  File "C:\Python27\lib\distutils\dist.py", line 972, in run_command
    cmd_obj.run()
  File "setup.py", line 297, in run
    init_msvc_env(OPTION_MSVCVERSION, platform_arch, log)
  File "C:\Users\r.prado\Desktop\PySide-1.2.0\utils.py", line 84, in init_msvc_e
nv
    raise DistutilsSetupError(
NameError: global name 'DistutilsSetupError' is not defined