[IronPython] Multiple engines keep barfing

[Brandon Furtwangler]

I'm making a simple AI game and I can load a ship up that runs a python
script to control its behavior.

My python script uses the random python library (ripped from CPython) and
works fine if I have one ship, but if I try to create another I get an
exception saying that 'None is not enumerable'.

It's in os.py on the line that says "if 'posix' in _names:".  (and _names =
sys.builtin_module_names)

I don't see why it should act any different with the second engine because
they are both going through the exact same code path:

pe.AddToPath(System.Windows.Forms.Application.StartupPath + @"\Lib");
pe.LoadAssembly(System.Reflection.Assembly.GetAssembly(typeof(Ship)));
pe.SetVariable("ship", this);
pe.ExecuteFile(aiscript);  <-- {"None is not enumerable"} from os.py


The script:

from IPExample import Action
import random

def GetAction():
    p = random.uniform(0.0,1.0)
    d = 0.0
    for i in range(0,6):
        d += actionProps[i]
        if p <= d:
            return allActions[i]
    return allActions[6]

allActions = [Action.RotateClockwise, Action.RotateCounterClockwise,
              Action.RotateGunClockwise, Action.RotateGunCounterClockwise,
              Action.Fire, Action.MoveForward, Action.ActivateShield]

actionProps = [0.1,0.1,0.05,0.05,0.2,0.4,0.1]

Any ideas on what I'm doing wrong?  Have others run into this?  Known bug?
Obviously sys.builtin_module_names is 'None' for some reason only on the
second engine...but why?

-Brandon