vscode-python: "RuntimeError: already started" after VSCode Update.

Environment data

VS Code version: 1.46.1
Extension version: v2020.6.89148
OS and version: Mint 19.3 Cinamon
Python version: Python3.6
Type of virtual environment used: virtualenv + virtualenvwrapper
Relevant/affected Python packages and their versions: XXX
Relevant/affected Python-related VS Code extensions and their versions: XXX
Jedi or Language Server? (i.e. what is "python.jediEnabled" set to; more info #3977): XXX
Value of the python.languageServer setting: XXX

I have been using VSCode to debug Python for almost a year now with the following run configuration from my launch.json file:

{
    "name": "Microservices",
    "type": "python",
    "request": "launch",
    "program": "/home/user/.virtualenvs/core-microservices/bin/gunicorn",
    "gevent": true,
    "args": [
        "main:app",
        "--bind=127.0.0.1:8080",
        "--worker-class",
        "eventlet",
        "-w",
        "4",
        "--timeout=7200"
    ],
    "envFile": "${workspaceFolder}/microservices.env",
    "postDebugTask": "killdebugger"
}

After the last update, when I try to run the debugger I get the following stack trace:

[2020-06-19 18:24:23 -0300] [18447] [INFO] Unhandled exception in main loop
Traceback (most recent call last):
  File "/home/mauricio/.virtualenvs/core-microservices/lib/python3.6/site-packages/gunicorn/arbiter.py", line 203, in run
    self.manage_workers()
  File "/home/mauricio/.virtualenvs/core-microservices/lib/python3.6/site-packages/gunicorn/arbiter.py", line 545, in manage_workers
    self.spawn_workers()
  File "/home/mauricio/.virtualenvs/core-microservices/lib/python3.6/site-packages/gunicorn/arbiter.py", line 616, in spawn_workers
    self.spawn_worker()
  File "/home/mauricio/.virtualenvs/core-microservices/lib/python3.6/site-packages/gunicorn/arbiter.py", line 567, in spawn_worker
    pid = os.fork()
  File "/home/mauricio/.vscode/extensions/ms-python.python-2020.6.89148/pythonFiles/lib/python/old_ptvsd/ptvsd/_vendored/pydevd/_pydev_bundle/pydev_monkey.py", line 528, in new_fork
    _on_forked_process()
  File "/home/mauricio/.vscode/extensions/ms-python.python-2020.6.89148/pythonFiles/lib/python/old_ptvsd/ptvsd/_vendored/pydevd/_pydev_bundle/pydev_monkey.py", line 50, in _on_forked_process
    pydevd.settrace_forked()
  File "/home/mauricio/.vscode/extensions/ms-python.python-2020.6.89148/pythonFiles/lib/python/old_ptvsd/ptvsd/_vendored/pydevd/pydevd.py", line 2427, in settrace_forked
    patch_multiprocessing=True,
  File "/home/mauricio/.vscode/extensions/ms-python.python-2020.6.89148/pythonFiles/lib/python/old_ptvsd/ptvsd/_vendored/pydevd/pydevd.py", line 2179, in settrace
    wait_for_ready_to_run,
  File "/home/mauricio/.vscode/extensions/ms-python.python-2020.6.89148/pythonFiles/lib/python/old_ptvsd/ptvsd/_vendored/pydevd/pydevd.py", line 2230, in _locked_settrace
    debugger.connect(host, port)  # Note: connect can raise error.
  File "/home/mauricio/.vscode/extensions/ms-python.python-2020.6.89148/pythonFiles/lib/python/old_ptvsd/ptvsd/_vendored/pydevd/pydevd.py", line 1060, in connect
    s = start_client(host, port)
  File "/home/mauricio/.vscode/extensions/ms-python.python-2020.6.89148/pythonFiles/lib/python/old_ptvsd/ptvsd/pydevd_hooks.py", line 136, in _start_client
    return start_client(daemon, h, p)
  File "/home/mauricio/.vscode/extensions/ms-python.python-2020.6.89148/pythonFiles/lib/python/old_ptvsd/ptvsd/log.py", line 110, in g
    return f(*args, **kwargs)
  File "/home/mauricio/.vscode/extensions/ms-python.python-2020.6.89148/pythonFiles/lib/python/old_ptvsd/ptvsd/pydevd_hooks.py", line 74, in start_client
    sock, start_session = daemon.start_client((host, port))
  File "/home/mauricio/.vscode/extensions/ms-python.python-2020.6.89148/pythonFiles/lib/python/old_ptvsd/ptvsd/daemon.py", line 214, in start_client
    with self.started():
  File "/usr/lib/python3.6/contextlib.py", line 81, in __enter__
    return next(self.gen)
  File "/home/mauricio/.vscode/extensions/ms-python.python-2020.6.89148/pythonFiles/lib/python/old_ptvsd/ptvsd/daemon.py", line 110, in started
    self.start()
  File "/home/mauricio/.vscode/extensions/ms-python.python-2020.6.89148/pythonFiles/lib/python/old_ptvsd/ptvsd/daemon.py", line 145, in start
    raise RuntimeError('already started')

Steps to reproduce:

[NOTE: Self-contained, minimal reproducing code samples are extremely helpful and will expedite addressing your issue]

Just try to debug a python application with the latest version of the VScode editor and the Python Extension as well.

Logs

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

XXX

Output from Console under the Developer Tools panel (toggle Developer Tools on under Help; turn on source maps to make any tracebacks be useful by running Enable source map support for extension debugging)

XXXX

About this issue

Original URL
State: closed
Created 4 years ago
Comments: 16

Most upvoted comments

This commit removes the experiment along with the old debugger, so it actually fixes this issue, in a sense. But it was only merged 3 days ago, so it’s only present in insiders build, not in stable.

(Consequently, if you want a quick workaround - just install insiders!)

int19h on Jun 22, 2020

Looks like everybody received the fix, so I’m going to go ahead and close this.

int19h on Jul 2, 2020

@int19h You are correct. I have just removed the options for “python.experiments.optInto” from my settings.json (which solved the issue originally for me) and my multiprocessing code still works! Great, thank you!

garrickbrazil on Jun 24, 2020

This should now be fixed. Can you please try restarting VSCode, and see if everything works for you now?

int19h on Jun 22, 2020

To work around without insiders build, please add the following to your settings.json:

    "python.experiments.optInto": [
        "DebugAdapterFactory - experiment",
        "PtvsdWheels37 - experiment"
    ],

To be clear, this is still a bug, and the above is a temporary workaround. We’re investigating the root cause.

int19h on Jun 22, 2020