Wrong code file is executed when switching tab shortly after "Start Debugging"

Environment data

• VS Code version: 1.42.0-insider (7c0095)
• Extension version (available under the Extensions sidebar): 2019.11.50794
• OS and version: Windows 10 1909
• Python version (& distribution if applicable, e.g. Anaconda): python.org, 3.8.1
• Type of virtual environment used (N/A | venv | virtualenv | conda | …): N/A
• Relevant/affected Python packages and their versions: none, I believe
• Jedi or Language Server? (i.e. what is "python.jediEnabled" set to; more info #3977): irrelevant, I believe

Expected behaviour

I intend to Start Debugging on a.py

Actual behaviour

b.py is debugged.

Steps to reproduce:

I mainly notice this when using VS Code Remote SSH. Happens with Windows (via Insiders) or Linux servers. Client system is on Windows. I should say that my client system is rather slow, so terminal output takes several seconds to scroll while I am starting debugging.

1. Create and open a.py [print(1)] and b.py [print(2)].
2. Activate a.py tab
3. Press F5 and immediately after that press Shift-Tab to activate b.py
4. If you’re fast enough, b.py is started and 2 is printed, while 1 should be printed.

Logs

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

> python c:\Users\bersbersbers\.vscode-server-insiders\extensions\ms-python.python-2019.11.50794\pythonFiles\interpreterInfo.py
> python c:\Users\bersbersbers\.vscode-server-insiders\extensions\ms-python.python-2019.11.50794\pythonFiles\interpreterInfo.py
> python -c "import sys;print(sys.executable)"
> python -c "import sys;print(sys.executable)"
> python -c "import sys;print(sys.executable)"
> python -c "import sys;print(sys.executable)"

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)

console.ts:137 [Extension Host] Error Python Extension: 2020-01-04 19:50:31: Failed to create File hash for interpreter python [Error: ENOENT: no such file or directory, lstat 'C:\Users\bersbersbers\.vscode-server-insiders\bin\7c0095ee2d064033fc13184127a9adc603454729\python'] {  errno: -4058,  code: 'ENOENT',  syscall: 'lstat',  path: 'C:\\Users\\bersbersbers\\.vscode-server-insiders\\bin\\7c0095ee2d064033fc13184127a9adc603454729\\python'}
t.log @ console.ts:137
$logExtensionHostMessage @ mainThreadConsole.ts:39
_doInvokeHandler @ rpcProtocol.ts:398
_invokeHandler @ rpcProtocol.ts:383
_receiveRequest @ rpcProtocol.ts:299
_receiveOneMessage @ rpcProtocol.ts:226
(anonymous) @ rpcProtocol.ts:101
fire @ event.ts:581
fire @ ipc.net.ts:453
_receiveMessage @ ipc.net.ts:733
(anonymous) @ ipc.net.ts:592
fire @ event.ts:581
acceptChunk @ ipc.net.ts:239
(anonymous) @ ipc.net.ts:200
t @ ipc.net.ts:28
emit @ events.js:200
addChunk @ _stream_readable.js:294
readableAddChunk @ _stream_readable.js:275
Readable.push @ _stream_readable.js:210
onStreamRead @ internal/stream_base_commons.js:166
console.ts:137 [Extension Host] Info Python Extension: 2020-01-04 19:50:31: Cached data exists getEnvironmentVariables, <No Resource>
2console.ts:137 [Extension Host] Info Python Extension: 2020-01-04 19:50:31: > python c:\Users\bersbersbers\.vscode-server-insiders\extensions\ms-python.python-2019.11.50794\pythonFiles\interpreterInfo.py
log.ts:196   ERR TreeError [MarkersView] Tree element not found: [object Object]: Error: TreeError [MarkersView] Tree element not found: [object Object]
    at t.ObjectTreeModel.getElementLocation (file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:134:704)
    at t.ObjectTreeModel.isCollapsed (file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:133:842)
    at K.isCollapsed (file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:1058:208)
    at U.autoReveal (file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:6127:205)
    at U.onActiveEditorChanged (file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:6124:330)
    at file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:6123:162
    at file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:113:124
    at c.fire (file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:116:740)
    at e.doHandleActiveEditorChangeEvent (file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:5584:91)
    at e.handleActiveEditorChange (file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:5583:836)
    at file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:5584:201
    at c.fire (file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:116:740)
    at file:///C:/Users/bersbersbers/AppData/Local/Programs/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.desktop.main.js:5756:883
console.ts:137 [Extension Host] Info Python Extension: 2020-01-04 19:50:32: Cached data exists getEnvironmentVariables, c:\Src\cia
2console.ts:137 [Extension Host] Info Python Extension: 2020-01-04 19:50:32: > python -c "import sys;print(sys.executable)"

[bersbersbers]

Alright, thanks for the explanation. I was suspecting that there must have been more to your argument than “I am too fast for my machine” 😃 I will accept this as a hard-to-solve architecture artifact and will use your proposed workaround. Thanks!

[karrtikr]

Unfortunately we can’t do much about it, as you’re faster than the machine. You could use "program": "${workspaceFolder}/b.py" if you want to run any specific files, closing this.