Error when trying to debug pyramid app on Windows

[isoengas]

Environment data

VS Code version: 1.20.0
Python Extension version: 2018.1.0
Python Version: 3.6.3
OS and version: Windows 10

Actual behavior

Using the default 'Python Pyramid' debug config throws an exception in the debug console:
ValueError: source code string cannot contain null bytes

Expected behavior

Debugger working

Not sure what additional information should be neccessary..

[brettcannon]

I can verify this with the following example code by simply trying to run it under the debugger:

from wsgiref.simple_server import make_server
from pyramid.config import Configurator
from pyramid.response import Response


def hello_world(request):
    return Response('Hello %(name)s!' % request.matchdict)

if __name__ == '__main__':
    with Configurator() as config:
        config.add_route('hello', '/hello/{name}')
        config.add_view(hello_world, route_name='hello')
        app = config.make_wsgi_app()
    server = make_server('localhost', 8080, app)
    server.serve_forever()

[Nicknk]

Hello!
I have this problem with debug Pyramid application too. Before VSCode I have used PyCharm and have problem with pserve.exe in debugging. But it is correctly use pserve-script.py for start application in debug.
So I have hacked installed Python Extension (version: 2018.3.1) baseProvider.js - I have changed
const pserve = platformService.isWindows ? 'pserve.exe' : 'pserve'; to
const pserve = platformService.isWindows ? 'pserve-script.py' : 'pserve'; and now I can debug Pyramid Application.

But when started debug, application stop in 'version.py' on string 220, but after pressing F5 (Continue) application start and can be debugging.

May be my experiment help you check this bug.

[DonJayamanne]

@Nicknk
Thanks for your PR, but I've started looking into this in a separate issue as well in #1483 and #1467.

[DonJayamanne]

Looking at the code on how pserve works, we'll need implement a different solution.
In the old debugger, we got things working by passing in the executable as the python program that needs to be run. It doesn't seem to work on Windows (as reported by OP and @Nicknk) and doesn't seem to work in the new (experimental) debugger either.

The code that bootstrap a pyramid application is found in bin/pserve, all this does is run the main method found in pyramid/scripts/pserve.py.
So the proper solution would be to simply run the above python file.

@Nicknk @isoengas What versions of Pyramid do you have installed?

[DonJayamanne]

@Nicknk until this is fixed you can change the launch.json as follows:

• Remove the Pyramid setting from debugOptions
• Change the program value to point to the file pyramid/scripts/pserve.py (please use the fully qualified path to the above file, found in the site_packages directory).

[isoengas]

I can confirm that the solution proposed by @DonJayamanne is working on both the regular & experimental debuggers.

Thanks for your support!

I'm on pyramid 1.9.1, BTW and this is my launch.json:

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Pyramid",
            "type": "python",
            "request": "launch",
            "program": "<full path to pserve.py>",
            "args": [
                "${workspaceFolder}/development.ini"
            ],
            "debugOptions": [
                "RedirectOutput"
            ]
        },
        {
            "name": "Pyramid Experimental",
            "type": "pythonExperimental",
            "request": "launch",
            "program": "<full path to pserve.py>",
            "args": [
                "${workspaceFolder}/development.ini"
            ]
        }
    ]
}

[Nicknk]

I can try solution - yes, it work with debuggers without problem.
@DonJayamanne, thanks for solution problem!

I am using Pyramid 1.9.1, VSCode 1.22.2 and Python 3.6.5 with virtual enviroment.