old_contents: #!/usr/bin/env python
  #
  # Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
  # for details. All rights reserved. Use of this source code is governed by a
  # BSD-style license that can be found in the LICENSE file.
  
  """
  Wrapper around a build action that should only be executed in release mode.
  
  The mode is defined via an environment varible DART_BUILD_MODE.
  
  The arguments to the script are:
  
    only_in_release_mode.py files... -- command arguments...
  
  If mode is not 'release', the script will create the files listed
  before --.  If mode is release, the script will execute the command
  after --.
  """
  
  import os
  import subprocess
  import sys
  
  
  def Main():
    # Throws an error if '--' is not in the argument list.
    separator_index = sys.argv.index('--')
    outputs = sys.argv[1:separator_index]
    arguments = sys.argv[separator_index + 1:]
    mode = os.getenv('DART_BUILD_MODE', default='release')
    if mode != 'release':
      print >> sys.stderr, 'Not running %s in mode=%s' % (arguments, mode)
      for output in outputs:
        with open(output, 'w'):
          # Create an empty file to ensure that we don't rerun this
          # command unnecessarily.
          pass
      return 0
    else:
      try:
        subprocess.check_call(arguments)
      except subprocess.CalledProcessError as e:
        return e.returncode
      return 0
  
  
  if __name__ == '__main__':
    sys.exit(Main())
  
new_contents: #!/usr/bin/env python
  #
  # Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
  # for details. All rights reserved. Use of this source code is governed by a
  # BSD-style license that can be found in the LICENSE file.
  
  """
  Wrapper around a build action that should only be executed in release mode.
  
  The mode is defined via an environment varible DART_BUILD_MODE.
  
  The arguments to the script are:
  
    only_in_release_mode.py files... -- command arguments...
  
  If mode is not 'release', the script will create the files listed
  before --.  If mode is release, the script will execute the command
  after --.
  """
  
  import os
  import subprocess
  import sys
  
  
  def Main():
    # Throws an error if '--' is not in the argument list.
    separator_index = sys.argv.index('--')
    outputs = sys.argv[1:separator_index]
    arguments = sys.argv[separator_index + 1:]
    arguments[0] = os.path.normpath(arguments[0])
    mode = os.getenv('DART_BUILD_MODE', default='release')
    if mode != 'release':
      print >> sys.stderr, 'Not running %s in mode=%s' % (arguments, mode)
      for output in outputs:
        with open(output, 'w'):
          # Create an empty file to ensure that we don't rerun this
          # command unnecessarily.
          pass
      return 0
    else:
      try:
        subprocess.check_call(arguments)
      except subprocess.CalledProcessError as e:
        return e.returncode
      return 0
  
  
  if __name__ == '__main__':
    sys.exit(Main())
  
subject: Fix only_in_release_mode.py's subcommand paths on Windows.