Comment 8 for bug 315223

I think I fixed this in r97358 (not released yet) with an extra check in the create_buildout_default_file in grokproject/utils.py:

     eggs_dir = os.path.join(default_dir, 'eggs')
     if not os.path.isdir(eggs_dir):
         os.mkdir(eggs_dir)
+ if sys.platform == 'win32':
+ import win32api
+ eggs_dir = win32api.GetShortPathName(eggs_dir)

Please check if this actually fixes it.