ptvsd hangs until typing in the Debug Console then fails with thread_id as Nonetype

[JoshuaC3]

Environment data

• PTVSD version: 2019.3.6558
• OS and version: Ubuntu 16.04
• Python version (& distribution if applicable, e.g. Anaconda): Anaconda Python 3.6.5
• Using VS Code or Visual Studio: VSCode

Actual behavior

The debugger hangs until you click in the Debug Console text entry box and start typing. At this point, the following error message appears:

Traceback (most recent call last):
:undefined
  File "/home/josh/.vscode/extensions/ms-python.python-2019.3.6558/pythonFiles/lib/python/ptvsd/_vendored/pydevd/_pydevd_bundle/pydevd_comm.py", line 284, in _on_run
:undefined
    self.process_net_command_json(self.global_debugger_holder.global_dbg, json_contents)
  File "/home/josh/.vscode/extensions/ms-python.python-2019.3.6558/pythonFiles/lib/python/ptvsd/_vendored/pydevd/_pydevd_bundle/pydevd_process_net_command_json.py", line 137, in process_net_command_json
:undefined
    cmd = on_request(py_db, request)
  File "/home/josh/.vscode/extensions/ms-python.python-2019.3.6558/pythonFiles/lib/python/ptvsd/_vendored/pydevd/_pydevd_bundle/pydevd_process_net_command_json.py", line 177, in on_completions_request
:undefined
    self.api.request_completions(py_db, seq, thread_id, frame_id, text, line=line, column=column)
  File "/home/josh/.vscode/extensions/ms-python.python-2019.3.6558/pythonFiles/lib/python/ptvsd/_vendored/pydevd/_pydevd_bundle/pydevd_api.py", line 118, in request_completions
:undefined
    thread_id, internal_get_completions, seq, thread_id, frame_id, act_tok, line=line, column=column)
  File "/home/josh/.vscode/extensions/ms-python.python-2019.3.6558/pythonFiles/lib/python/ptvsd/_vendored/pydevd/pydevd.py", line 843, in post_method_as_internal_command
:undefined
    self.post_internal_command(internal_cmd, thread_id)
  File "/home/josh/.vscode/extensions/ms-python.python-2019.3.6558/pythonFiles/lib/python/ptvsd/_vendored/pydevd/pydevd.py", line 847, in post_internal_command
:undefined
    queue = self.get_internal_queue(thread_id)
  File "/home/josh/.vscode/extensions/ms-python.python-2019.3.6558/pythonFiles/lib/python/ptvsd/_vendored/pydevd/pydevd.py", line 834, in get_internal_queue
:undefined
    if thread_id.startswith('__frame__'):
AttributeError: 'NoneType' object has no attribute 'startswith'

Expected behavior

The debugger to run.

Other Info

I also tried the previous release, with the same issue - (61xx)

I also tried the release before that - (5xxx). The failed on another error. I can reproduce this if needed.

Steps to reproduce:

1. Run Debug Console for Flask as per settings and launch.

setting.json

``` { "workbench.colorTheme": "Solarized Light", "explorer.confirmDragAndDrop": false, "python.pythonPath": "/home/josh/miniconda3/envs/python-data-converter-dev/bin/python", "git.confirmSync": false, "python.formatting.provider": "autopep8", "editor.formatOnSave": true, "python.linting.flake8Enabled": true, "python.unitTest.unittestEnabled": false, "python.unitTest.pyTestEnabled": true, "python.unitTest.nosetestsEnabled": false, "python.unitTest.autoTestDiscoverOnSaveEnabled": true, "python.unitTest.pyTestPath": "pytest", "python.unitTest.pyTestArgs": [ "tests", "--no-cov" ], "files.exclude": { "**/__pycache__": true, "**/.ipynb_checkpoints": true, "**/.pytest_cache": true, "**/*.egg-info": true } } ```

launch.json

``` { // Use IntelliSense to learn about possible attributes. // Hover to view descriptions of existing attributes. // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387 "version": "0.2.0", "configurations": [ { "name": "Python: Current File (Integrated Terminal)", "type": "python", "request": "launch", "program": "${file}", "console": "integratedTerminal" }, { "name": "Python: Remote Attach", "type": "python", "request": "attach", "port": 5678, "host": "localhost", "pathMappings": [ { "localRoot": "${workspaceFolder}", "remoteRoot": "." } ] }, { "name": "Python: Module", "type": "python", "request": "launch", "module": "enter-your-module-name-here", "console": "integratedTerminal" }, { "name": "Python: Django", "type": "python", "request": "launch", "program": "${workspaceFolder}/manage.py", "console": "integratedTerminal", "args": [ "runserver", "--noreload", "--nothreading" ], "django": true }, { "name": "Python: Flask", "type": "python", "request": "launch", "module": "flask", "env": { "FLASK_APP": "data_converter/webhook.py", "FLASK_ENV": "development" }, "args": [ "run", "--no-debugger", "--no-reload" ], "jinja": true }, { "name": "Python: Current File (External Terminal)", "type": "python", "request": "launch", "program": "${file}", "console": "externalTerminal" } ] } ```

[zvictor]

I am having the same on Mac. I commented out my whole settings.json to be sure it was not a problem connected to any of my personal settings and the problem persisted.

@karthiknadig Issue #1329 did not affect me:

Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/ptvsd/_vendored/pydevd/_pydevd_bundle/pydevd_comm.py", line 284, in _on_run
    self.process_net_command_json(self.global_debugger_holder.global_dbg, json_contents)
  File "/usr/local/lib/python3.7/site-packages/ptvsd/_vendored/pydevd/_pydevd_bundle/pydevd_process_net_command_json.py", line 137, in process_net_command_json
    cmd = on_request(py_db, request)
  File "/usr/local/lib/python3.7/site-packages/ptvsd/_vendored/pydevd/_pydevd_bundle/pydevd_process_net_command_json.py", line 177, in on_completions_request
    self.api.request_completions(py_db, seq, thread_id, frame_id, text, line=line, column=column)
  File "/usr/local/lib/python3.7/site-packages/ptvsd/_vendored/pydevd/_pydevd_bundle/pydevd_api.py", line 118, in request_completions
    thread_id, internal_get_completions, seq, thread_id, frame_id, act_tok, line=line, column=column)
  File "/usr/local/lib/python3.7/site-packages/ptvsd/_vendored/pydevd/pydevd.py", line 843, in post_method_as_internal_command
    self.post_internal_command(internal_cmd, thread_id)
  File "/usr/local/lib/python3.7/site-packages/ptvsd/_vendored/pydevd/pydevd.py", line 847, in post_internal_command
    queue = self.get_internal_queue(thread_id)
  File "/usr/local/lib/python3.7/site-packages/ptvsd/_vendored/pydevd/pydevd.py", line 834, in get_internal_queue
    if thread_id.startswith('__frame__'):
AttributeError: 'NoneType' object has no attribute 'startswith'

[fabioz]

I haven't been able to reproduce, but looking at the code it seems that in on_completions_request, py_db.suspended_frames_manager.get_thread_id_for_variable_reference could return None as the thread_id if the frame_id is no longer valid (so, we should at least check if that's the case and return an error instead of showing an exception).

[fabioz]

As a note, I've been able to reproduce in a test case when it asks for completions of a frame which is no longer paused (so, it may be a race condition -- which we should account for).

[SimeonRolev]

@fabioz This issue happens to me with 2019.4.12954 too. The only difference is that it does not break when I start typing something, but when I hit Enter.

[fabioz]

@SimeonRolev

Can you provide the stack trace?

A recent commit (e44dc09) fixed another issue where the thread id could be none evaluating expressions -- which I think could be the culprit in your case (same issue in a different place -- but should be fixed in master already).

[SimeonRolev]

@fabioz I think the stack trace is the same. I just removed the Python extension and added it back, so I assume I have the latest version.

import logging
not available
Traceback (most recent call last):
  File "c:\Users\simeon rolev\.vscode\extensions\ms-python.python-2019.4.12954\pythonFiles\lib\python\ptvsd\_vendored\pydevd\_pydevd_bundle\pydevd_comm.py", line 284, in _on_run
    self.process_net_command_json(self.global_debugger_holder.global_dbg, json_contents)
  File "c:\Users\simeon rolev\.vscode\extensions\ms-python.python-2019.4.12954\pythonFiles\lib\python\ptvsd\_vendored\pydevd\_pydevd_bundle\pydevd_process_net_command_json.py", line 157, in process_net_command_json
    cmd = on_request(py_db, request)
  File "c:\Users\simeon rolev\.vscode\extensions\ms-python.python-2019.4.12954\pythonFiles\lib\python\ptvsd\_vendored\pydevd\_pydevd_bundle\pydevd_process_net_command_json.py", line 559, in on_evaluate_request
    py_db, request, thread_id)
  File "c:\Users\simeon rolev\.vscode\extensions\ms-python.python-2019.4.12954\pythonFiles\lib\python\ptvsd\_vendored\pydevd\_pydevd_bundle\pydevd_api.py", line 385, in request_exec_or_evaluate_json
    thread_id, internal_evaluate_expression_json, request, thread_id)
  File "c:\Users\simeon rolev\.vscode\extensions\ms-python.python-2019.4.12954\pythonFiles\lib\python\ptvsd\_vendored\pydevd\pydevd.py", line 873, in post_method_as_internal_command
    self.post_internal_command(internal_cmd, thread_id)
  File "c:\Users\simeon rolev\.vscode\extensions\ms-python.python-2019.4.12954\pythonFiles\lib\python\ptvsd\_vendored\pydevd\pydevd.py", line 877, in post_internal_command
    queue = self.get_internal_queue(thread_id)
  File "c:\Users\simeon rolev\.vscode\extensions\ms-python.python-2019.4.12954\pythonFiles\lib\python\ptvsd\_vendored\pydevd\pydevd.py", line 864, in get_internal_queue
    if thread_id.startswith('__frame__'):
AttributeError: 'NoneType' object has no attribute 'startswith'

[fabioz]

Actually, this one is not fixed (it's in a different place: on_evaluate_request).

Created: #1401 to deal with that as it's similar but not the same thing.