[Pharo-users] Trying to understand OSProcess on MacOS Yosemite

So I try to understand how OSProcess work exactly to find why filetree seems not able to use it and generating the error I already reported earlier. Using something simple like OSProcess command:'pwd' works great , I have the terminal open and I can see the correct return value of the command in my terminal but for some reason I can find no such info when I inspect the above example. So how exactly OSProcess returns the output of the terminal ? Is there an instance variable of some sort ? Because I tried to inspect it deeply and I found nothing . Can you help me understand how OSProcess work ? Because If I do understand it then I can find what the problem is .