I am getting the following error while running gclient runhooks for building chromium.

running '/usr/bin/python src/tools/clang/scripts/update.py --if-needed' in '/media/usrname/!!ChiLL out!!'
Traceback (most recent call last):
File "src/tools/clang/scripts/update.py", line 283, in 
      sys.exit(main())
File "src/tools/clang/scripts/update.py", line 269, in main
      stderr=os.fdopen(os.dup(sys.stdin.fileno())))
File "/usr/lib/python2.7/subprocess.py", line 522, in call
      return Popen(*popenargs, **kwargs).wait()
  File "/usr/lib/python2.7/subprocess.py", line 710, in init
      errread, errwrite)
File "/usr/lib/python2.7/subprocess.py", line 1327, in _execute_child
      raise child_exception
OSError: [Errno 13] Permission denied
  Error: Command /usr/bin/python src/tools/clang/scripts/update.py --if-needed returned non-zero exit status 1 in /media/usrname/!!ChiLL out!!

In order to get permission of the directory "/usr/bin/python src/tools/clang/scripts" I tried chown and chmod but it returned the same error.
Actually the directory was not mounted with execution permission. So I remounted the directory with execution permission using
mount -o exec /dev/sda5 /media/usrname
 and it worked fine.
Chromium build gclient runhooks error number 13