systrace.py error : in _execute_child raise child_exception

$ cd android-sdk/platform-tools/systrace$ python systrace.py --time=10 -o mynewtrace.html sched gfx view wm
Traceback (most recent call last):File "./systrace.py", line 212, in <module>main()File "./systrace.py", line 121, in mainstderr=subprocess.PIPE)File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py",    line 679, in __init__errread, errwrite)File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 1249, in _execute_childraise child_exceptionOSError: [Errno 2] No such file or directory

Solution:
it looks like the script assumes adb is in your path. add the platform-tools sdk dir to your path and it should work.

http://stackoverflow.com/questions/11823007/systrace-android-no-such-file-or-directory