native client + hermetic toolchain + gn

src/trusted/service_runtime/osx/run_mig.py

 #!/usr/bin/python
 # Copyright (c) 2012 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Generate a mig server and client pair from migs.def
 # Emitting:
 #     nacl_exc_server.c
 #     nacl_exc.h
 
@@ skipping 65 matching lines @@
       del os.environ['SDKROOT']
 
     args.append(nacl_exc_defs_path)
     subprocess.check_call(args)
   finally:
     if nacl_exc_defs_path and os.path.exists(nacl_exc_defs_path):
       os.remove(nacl_exc_defs_path)
 
 
 def Main(args):
-  if len(args) != 3:
+  if len(args) != 4:
     sys.stderr.write(
         'USAGE: %s <src.defs> <dst_header> <dst_server>\n' % sys.argv[0])
     sys.exit(1)
+  os.environ['DEVELOPER_DIR'] = sys.argv[4]
   Generate(args[0], args[1], args[2])
 
 
 if __name__ == '__main__':
   Main(sys.argv[1:])