message: farm: create the directory before using it
diff: @@ -174,14 +174,15 @@ elif options.os == 'windows':
  else:
  raise Exception('invalid OS: %s' % options.os)
  -with open('%s/.drake.tmp' % options.build_dir, 'w') as drake:
  +build_dir = options.build_dir
  +os.makedirs(build_dir, exist_ok = True)
  +
  +with open('%s/.drake.tmp' % build_dir, 'w') as drake:
  parameters['source_dir'] = os.path.realpath(options.source_dir)
  parameters['install_dir'] = os.path.realpath(options.install_dir)
  content = template % parameters
  print(content, file = drake)
  -build_dir = options.build_dir
  -os.makedirs(build_dir, exist_ok = True)
  tmp = '%s/.drake.tmp' % build_dir
  drake = '%s/drake' % build_dir
  subprocess.call(['diff', '-u', drake if os.path.isfile(drake) else '/dev/null', tmp])
  