Fix bootstrap on windows

recipes.py

 #!/usr/bin/env python
 # Copyright 2015 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 """Tool to interact with recipe repositories.
 
 This tool operates on the nearest ancestor directory containing an
 infra/config/recipes.cfg.
 """
 
 import argparse
 import json
 import logging
+import platform
 import os
 import subprocess
 import sys
 
 ROOT_DIR = os.path.dirname(os.path.abspath(__file__))
 sys.path.insert(0, os.path.join(ROOT_DIR, 'recipe_engine', 'third_party'))
 sys.path.insert(0, ROOT_DIR)
 
 def get_package_config(args):
   from recipe_engine import package
@@ skipping 358 matching lines @@
   args = parser.parse_args()
 
   if args.use_bootstrap and not os.environ.pop('RECIPES_RUN_BOOTSTRAP', None):
     subprocess.check_call(
         [sys.executable, 'bootstrap/bootstrap.py', '--deps-file',
          'bootstrap/deps.pyl', 'ENV'],
         cwd=os.path.dirname(os.path.realpath(__file__)))
 
     os.environ['RECIPES_RUN_BOOTSTRAP'] = '1'
     args = sys.argv
-    return subprocess.call(
-        [os.path.join(
-            os.path.dirname(os.path.realpath(__file__)), 'ENV/bin/python'),
-         os.path.join(ROOT_DIR, 'recipes.py')] + original_sys_argv[1:])
+    executable = ('python.exe' if sys.platform.lower() in (
+            'win32', 'cygwin') else 'python')
+    return subprocess.call([os.path.join(
+      ROOT_DIR, 'ENV', 'bin', executable),
+      os.path.join(ROOT_DIR, 'recipes.py')] + original_sys_argv[1:])
 
   if args.verbose:
     logging.getLogger().setLevel(logging.INFO)
 
   # Commands which do not require config_file, package_deps, and other objects
   # initialized later.
   if args.command == 'remote':
     return remote(args)
 
   repo_root, config_file = get_package_config(args)
@@ skipping 55 matching lines @@
   ret = main()
   if not isinstance(ret, int):
     if ret is None:
       ret = 0
     else:
       print >> sys.stderr, ret
       ret = 1
   sys.stdout.flush()
   sys.stderr.flush()
   os._exit(ret)