Output better error messages during build

build/android/process_resources.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Process Android library resources to generate R.java and crunched images."""
 
 import optparse
 import os
 import shlex
-import subprocess
 
 from pylib import build_utils
 
 def ParseArgs():
   """Parses command line options.
 
   Returns:
     An options object as from optparse.OptionsParser.parse_args()
   """
   parser = optparse.OptionParser()
@@ skipping 50 matching lines @@
                      '-I', android_jar,
                      '--output-text-symbols', options.R_dir,
                      '-J', options.R_dir]
   res_dirs = shlex.split(options.res_dirs)
   for res_dir in res_dirs:
     package_command += ['-S', res_dir]
   if options.non_constant_id:
     package_command.append('--non-constant-id')
   if options.custom_package:
     package_command += ['--custom-package', options.custom_package]
-  subprocess.check_call(package_command)
+  build_utils.CheckCallDie(package_command)
 
   # Crunch image resources. This shrinks png files and is necessary for 9-patch
   # images to display correctly.
   build_utils.MakeDirectory(options.crunch_output_dir)
-  subprocess.check_call([aapt,
-                         'crunch',
-                         '-S', options.crunch_input_dir,
-                         '-C', options.crunch_output_dir])
 
-  build_utils.Touch(options.stamp)
+  aapt_cmd = [aapt,
+              'crunch',
+              '-S', options.crunch_input_dir,
+              '-C', options.crunch_output_dir]
+  build_utils.CheckCallDie(aapt_cmd)
+
+  if options.stamp:
+    build_utils.Touch(options.stamp)
 
 
 if __name__ == '__main__':
   main()