runserver crashes because of auto-reloader (Py3 + PowerShell)

[oTree-org]

Repro steps:

• Install Python 3.x (doesn't happen on 2.x)
• Open Windows PowerShell (only happens with PowerShell, not CMD or bash)
• pip install django
• django-admin startproject foobar
• cd foobar
• python manage.py runserver

This causes a Windows crash with a window that says: "Python has stopped working": ​http://imgur.com/dOt6eKE

However, python manage.py runserver --noreload works fine, so it seems related to the auto-reloader.

Here is the info from the Windows Event Viewer:

Faulting application name: python.exe, version: 3.5.1150.1013
Faulting module name: ucrtbase.dll, version: 10.0.14393.0
Exception code: 0xc0000005
Faulting module path: C:\WINDOWS\System32\ucrtbase.dll

I have seen it happen with at least 5 people using Py3 & PowerShell, with Windows 8 or 10, and various PC models. (Though most people seem unaffected.)

Occurs with Django 1.8/1.10 and Python 3.5/3.6, maybe others also.