come on, this is how you drive-by

bin/sync-and-gyp

 #!/usr/bin/env python
 
 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This script will update Skia's dependencies as necessary and run
 # gyp if needed.
 
 # Depends on: Python, Git, and depot_tools.
 #
 # Example usage:
 #
 #   git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
 #   export PATH="${PWD}/depot_tools:${PATH}"
 #   git clone https://skia.googlesource.com/skia
 #   cd skia
 #   python bin/sync-and-gyp
 #   ninja -C out/Debug && out/Debug/dm
 #
 # Once changes are made to DEPS or gyp/ or the source, call:
 #
 #   python bin/sync-and-gyp
 
 import fnmatch
 import hashlib
 import subprocess
 import os
+import sys
 
 skia_dir = os.path.join(os.path.dirname(__file__), os.pardir)
 
 skia_out = os.environ.get("SKIA_OUT")
 if skia_out:
   skia_out = os.path.abspath(skia_out)
   hash_path = os.path.join(skia_out, 'gyp_hash')
 else:
   hash_path = os.path.join('out', 'gyp_hash')
 
@@ skipping 74 matching lines @@
       return f.read()
   return ''
 
 if cat_if_exists(hash_path).strip() != gyp_hash:
   env = os.environ.copy()
   if skia_out:
     env['SKIA_OUT'] = skia_out
   subprocess.call(['python', './gyp_skia'], env=env)
   with open(hash_path, 'w') as o:
     o.write(gyp_hash)