Flask app hangs on request after bundling with cx_freeze

Question

I've made a Flask app in Python which I want to turn into an exe for distribution, for that I'm trying to use cx_freeze.

When I run the app from Python or Pycharm, it works perfectly, but after I bundle it up, every request just hangs (spins in chrome). I tried debugging it and ended up creating a new flask app with just one route and no other dependencies, and the same thing happens.

Here's the test app I made (testapp/app.py):

from flask import Flask

# Create flask app
webapp = Flask(__name__)

@webapp.route('/')
def home():
    print "home"
    return 'hello there'

The setup.py for it:

from setuptools import find_packages
from cx_Freeze import setup, Executable

setup(
    name='testapp',
    description='Test Flask App',
    packages=find_packages(),
    include_package_data=True,
    zip_safe=False,
    install_requires=[
        'Flask',
        'waitress',
    ],
    options={
        "build_exe": {
            "packages": [
                "flask",
                "waitress",
                "threading",
                "os",
            ],
            'include_msvcr': True,
        }
    },
    executables=[
        Executable(
            "run.py",
            icon="icon.ico",
        )
    ]
)

And the run.py which serves as my entry point

from testapp.app import webapp
import sys
import waitress

if __name__ == "__main__":
    PORT = sys.argv[1] if len(sys.argv) > 1 else 8080
    waitress.serve(webapp, port=PORT)

I've read a few other questions but it seems to always end up being a templating problem, but this app isn't using templates and neither is my real app.

When I run it normally I get the output below and the page says "hello" to me

Serving on http://Desktop-PC:8080
home

When I run it as an exe, I get the same console output but the page just hangs.

I'm using flask==0.12 and cx-Freeze==5.0.1

Any ideas on how I can debug this one?

Edit:

I've noticed that during build time, I get a lot of warnings about missing packages, but if I try add those packages to my setup.py, cx_freeze throws errors about not being able to import them. But if I can't import them, and my app apparently needs them, shouldn't it fail to run normally?

List is a bit long, so it's in a gist

Answer 1

This ended up being a bug in cx_Freeze 5.0.1 which is now patched in cx_Freeze 5.0.2.