depswriter.py does not work in OSX

[GoogleCodeExporter]

What steps will reproduce the problem?
1. In the terminal window, go to your project directory
2. Execute the depswriter.py program with a root prefix path as described in 
the tutorials:

$ closure-library/closure/bin/build/depswriter.py  \
    --root_with_prefix="myproject ../../myproject" \
    > myproject-deps.js

What is the expected output? What do you see instead?
Expected that the script would execute.  

Instead got " IOError: [Errno 2] No such file or directory: ..."

No variation of the path does not product an error. Including running without 
the root_with_prefix like so:

$ closure-library/closure/bin/build/depswriter.py  \   > myproject-deps.js

What version of the product are you using? On what operating system?
Mac OSX Lion 
Closure-Library version 2.0

Please provide any additional information below.

Note: we cannot accept patches without the contributor license agreement
being signed. See http://code.google.com/p/closure-
library/wiki/Contributors for more info.

Original issue reported on code.google.com by j...@johnjmills.com on 8 Feb 2013 at 11:40

[GoogleCodeExporter]

If you are still having problems with this, please provide more details about 
where your source files are and where depswriter and closure library is in your 
file system.

I'm running under Mac OS X 10.6 "Snow Leopard" and depswriter is working for 
me.  The root_with_prefix is a little tricky because it needs to have the path 
back to your sources from closure-library/closure/bin.

This shows where I have depswriter:

[12:43:36 ~/Documents/Programming/javascript/closure-library/closure/bin]$ ls 
build
closurebuilder.py   depstree_test.py    jscompiler.pyc      source_test.py
depstree.py     depswriter.py       source.py       treescan.py
depstree.pyc        jscompiler.py       source.pyc      treescan.pyc

This is where my source is:

[12:44:46 ~/Documents/Programming/jssimlab]$ ls src
lab sims    test

This shows using the path back from closure/bin to my source directory:

[12:43:42 ~/Documents/Programming/javascript/closure-library/closure/bin]$ ls 
../../../../jssimlab/src
lab sims    test

This is the command to use depswriter, executed from above my source directory.

[12:44:54 ~/Documents/Programming/jssimlab]$ 
../javascript/closure-library/closure/bin/build/depswriter.py 
--root_with_prefix="src ../../../../jssimlab/src" > build/deps.js

Original comment by neum...@gmail.com on 2 Jun 2013 at 7:51