with statement is not supported

import spidermonkey

rt = spidermonkey.Runtime()
cx = rt.new_context()

cx.execute("""
        function f(o) {
            with (o) {
                return test;
            }
        }
""");

print cx.execute("f({'test' : 'toto'});");

f = cx.execute("f");
print f({'test' : 'toto'})

Results in:

$ python test.py 
toto
Traceback (most recent call last):
  File "test.py", line 18, in <module>
    print f({'test' : 'toto'})
RuntimeError: Failed to execute JS Function.