Redirect tput stderr to /dev/null.

dart/tools/build.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2012, 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.
 #
 
 import optparse
 import os
 import re
@@ skipping 250 matching lines @@
   section = None
   chunk = []
   # Is stdout a terminal which supports colors?
   is_fancy_tty = False
   clr_eol = None
   if sys.stdout.isatty():
     term = os.getenv('TERM', 'dumb')
     # The capability "clr_eol" means clear the line from cursor to end
     # of line.  See man pages for tput and terminfo.
     try:
-      clr_eol = subprocess.check_output(['tput', '-T' + term, 'el'],
-                                        stderr=subprocess.STDOUT)
+      with open('/dev/null', 'a') as dev_null:
+        clr_eol = subprocess.check_output(['tput', '-T' + term, 'el'],
+                                          stderr=dev_null)
       if clr_eol:
         is_fancy_tty = True
     except subprocess.CalledProcessError:
       is_fancy_tty = False
   pattern = re.compile(r'=== BUILD .* TARGET (.*) OF PROJECT (.*) WITH ' +
                        r'CONFIGURATION (.*) ===')
   has_interesting_info = False
   for line in unbuffered(process.stdout.readline):
     line = line.rstrip()
     if line.startswith('=== BUILD ') or line.startswith('** BUILD '):
@@ skipping 141 matching lines @@
         process.wait()
         if process.returncode != 0:
           print "BUILD FAILED"
           return 1
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(Main())