Debugger not hitting breakpoint when using a virtual environment

From @georgebridgeman on April 24, 2017 21:13

I cannot get the debugger to stop at breakpoints when my project is using a virtual environment created using the Python venv module.

I have tried specifying the absolute path to Python in the pythonPath property in launch.json and launching VS Code from the command line, as suggested in issues #91 and #148 but still cannot get it to work.

The code in this example (a simple print statement) debugs fine when a project is not created in a venv.

Environment data

VS Code version: 1.11.2 Python Extension version: 0.6.3 Python Version: 3.6.0 OS and version: MacOS X 10.11.6

Actual behavior

Debugger runs and output is written to Debug Console, but breakpoints are not hit.

Expected behavior

Debugger should break on breakpoints.

Steps to reproduce:

• cd ~/Projects
• python3 -m venv TestVenv
• cd TestVenv
• source bin/activate
• echo 'print("Hello, world!")' > test.py
• code .
• Open test.py in the editor
• Apply attached launch.json with absolute path to Python
• Switch back to test.py, add a breakpoint to line 1 and run debugger using F5
• Observe the output in Debug Console despite the breakpoint having no effect

Settings

Your launch.json (if dealing with debugger issues):

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Python",
            "type": "python",
            "request": "launch",
            "stopOnEntry": true,
            "pythonPath": "/Users/george/Projects/TestVenv/bin/python",
            "program": "${file}",
            "cwd": "${workspaceRoot}",
            "env": {},
            "envFile": "${workspaceRoot}/.env",
            "debugOptions": [
                "WaitOnAbnormalExit",
                "WaitOnNormalExit",
                "RedirectOutput"
            ]
        }
    ]
}

Your settings.json:
No settings.json file in the project.

Logs

Output from Python output panel

----------Generating Tags----------
ctags --options=/Users/george/.vscode/extensions/donjayamanne.python-0.6.3/resources/ctagOptions --languages=Python --exclude=**/site-packages/** -o /Users/george/Projects/TestVenv/.vscode/tags .
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ctags: illegal option -- -
usage: ctags [-BFadtuwvx] [-f tagsfile] file ...

Output from Console window (Help->Developer Tools menu)

shell.ts:475TypeError: Cannot read property 'Threads' of null
    at PythonDebugger.threadsRequest (/Users/george/.vscode/extensions/donjayamanne.python-0.6.3/out/client/debugger/Main.js:340:27)
    at PythonDebugger.DebugSession.dispatchRequest (/Users/george/.vscode/extensions/donjayamanne.python-0.6.3/node_modules/vscode-debugadapter/lib/debugSession.js:427:22)
    at PythonDebugger.ProtocolServer._handleData (/Users/george/.vscode/extensions/donjayamanne.python-0.6.3/node_modules/vscode-debugadapter/lib/protocol.js:104:38)
    at Socket.<anonymous> (/Users/george/.vscode/extensions/donjayamanne.python-0.6.3/node_modules/vscode-debugadapter/lib/protocol.js:24:60)
    at emitOne (events.js:96:13)
    at Socket.emit (events.js:188:7)
    at readableAddChunk (_stream_readable.js:176:18)
    at Socket.Readable.push (_stream_readable.js:134:10)
    at Pipe.onread (net.js:543:20): Error: TypeError: Cannot read property 'Threads' of null
    at PythonDebugger.threadsRequest (/Users/george/.vscode/extensions/donjayamanne.python-0.6.3/out/client/debugger/Main.js:340:27)
    at PythonDebugger.DebugSession.dispatchRequest (/Users/george/.vscode/extensions/donjayamanne.python-0.6.3/node_modules/vscode-debugadapter/lib/debugSession.js:427:22)
    at PythonDebugger.ProtocolServer._handleData (/Users/george/.vscode/extensions/donjayamanne.python-0.6.3/node_modules/vscode-debugadapter/lib/protocol.js:104:38)
    at Socket.<anonymous> (/Users/george/.vscode/extensions/donjayamanne.python-0.6.3/node_modules/vscode-debugadapter/lib/protocol.js:24:60)
    at emitOne (events.js:96:13)
    at Socket.emit (events.js:188:7)
    at readableAddChunk (_stream_readable.js:176:18)
    at Socket.Readable.push (_stream_readable.js:134:10)
    at Pipe.onread (net.js:543:20)
    at file:////Applications/Visual Studio Code.app/Contents/Resources/app/out/vs/workbench/electron-browser/workbench.main.js:28:2160295
    at Object.v [as _notify] (file:////Applications/Visual Studio Code.app/Contents/Resources/app/out/vs/workbench/electron-browser/workbench.main.js:28:50893)
    at Object.enter (file:////Applications/Visual Studio Code.app/Contents/Resources/app/out/vs/workbench/electron-browser/workbench.main.js:28:54394)
    at _run (file:////Applications/Visual Studio Code.app/Contents/Resources/app/out/vs/workbench/electron-browser/workbench.main.js:28:55715)
    at _error (file:////Applications/Visual Studio Code.app/Contents/Resources/app/out/vs/workbench/electron-browser/workbench.main.js:28:55232)
    at file:////Applications/Visual Studio Code.app/Contents/Resources/app/out/vs/workbench/electron-browser/workbench.main.js:28:1911266
    at g.e.dispatch (file:////Applications/Visual Studio Code.app/Contents/Resources/app/out/vs/workbench/electron-browser/workbench.main.js:28:1912617)
    at g.e.handleData (file:////Applications/Visual Studio Code.app/Contents/Resources/app/out/vs/workbench/electron-browser/workbench.main.js:28:1912125)
    at Socket.<anonymous> (file:////Applications/Visual Studio Code.app/Contents/Resources/app/out/vs/workbench/electron-browser/workbench.main.js:28:1911126)
    at emitOne (events.js:96:13)

Copied from original issue: DonJayamanne/pythonVSCode#913

[DonJayamanne]

@jonsagara Please could you try debugging using the new experimental debugger. Open your launch.json and change the type from python to pythonExperimental.

[brettcannon]

@DerfelKadarn since we’re not switching the experimental debugger to be the default one until we’re happy with its stability we don’t have an ETA.