Unable to debug flask after recent vscode upgrade

Environment data

• VS Code version: 1.27.1
• Extension version (available under the Extensions sidebar): 2018.8.0
• OS and version: macOS 10.13.6
• Python version (& distribution if applicable, e.g. Anaconda): Python 3.6.5
• Type of virtual environment used (N/A | venv | virtualenv | conda | …): none
• Relevant/affected Python packages and their versions: flask 1.0.2

Actual behavior

Breakpoint stops serving.py in the function serve_forever on line 612.

Expected behavior

Breakpoint should stop in my code on the line I set it. In this case it should be line 6 of app.py

Steps to reproduce:

1. create the following file app.py

from flask import Flask
app = Flask(__name__)

@app.route("/")
def hello():
    return "Hello World!"

1. start the application using the default launch configuration for flask in vs code
2. add a breakpoint on line 6 of app.py
3. start a browser and enter http://localhost:5000/
4. See how it breaks at the wrong location

Logs

Output for Python in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Python)

Starting Jedi Python language engine.
##########Linting Output - pylint##########

--------------------------------------------------------------------
Your code has been rated at 10.00/10 (previous run: 10.00/10, +0.00)

Output from Console under the Developer Tools panel (toggle Developer Tools on under Help)

bug/> cd /Users/stephengibson/Documents/github.ibm.com/bug ; env "FLASK_APP=app.py" "PYTHONIOENCODING=UTF-8" "PYTHONUNBUFFERED=1" "PYTHONPATH=/Users/stephengibson/.vscode/extensions/ms-python.python-2018.8.0/pythonFiles/experimental/ptvsd" /usr/local/bin/python3 -m ptvsd --host localhost --port 52628 -m flask run --no-debugger --no-reload
 * Serving Flask app "app.py"
 * Environment: production
   WARNING: Do not use the development server in a production environment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)

[dungeontiger]

@jchang10 @DonJayamanne Thanks. That’s exactly the issue. It seems to stop on the Main Thread but when I switch to the thread running my code I’m able to debug appropriately. I greatly appreciate the workaround.

I suppose you can close this issue as a duplicate.

[MandarJKulkarni]

After upgrading ptvsd to 4.1.2, unable to debug anything, neither flask nor ‘current file’ debugging is working.

Getting error “C:\Python27\python.exe: No module named ptvsd.main; ‘ptvsd’ is a package and cannot be directly executed”