Cannot launch multiple Python debug sessions using VSC API

Environment data

• VS Code version: 1.37.1
• Extension version (available under the Extensions sidebar): 2019.9.34474
• OS and version: Win10
• Python version (& distribution if applicable, e.g. Anaconda): 2.7
• Type of virtual environment used (N/A | venv | virtualenv | conda | …): N/A
• Relevant/affected Python packages and their versions: N/A
• Jedi or Language Server? (i.e. what is "python.jediEnabled" set to; more info #3977): N/A

Expected behaviour

multiple Python debug sessions get launched upon executing the following code inside an extension:

for (let request of launchRequests) {
    request.executable = request.executable.toLowerCase();
    if (request.executable.endsWith("python") || request.executable.endsWith("python.exe")) {
        const pythonScript: string = request.arguments.shift();
        const pythonlaunchdebugconfiguration: vscode.DebugConfiguration = {
            name: `Python: launch`,
            type: "python",
            request: "launch",
            program: pythonScript,
            args: request.arguments,
            env: request.env,
            stopOnEntry: true,
        };
        vscode.debug.startDebugging(undefined, pythonlaunchdebugconfiguration);
    }
}

Actual behaviour

only 1 debug session gets launched, other debug sessions would hit a timeout error like this:

Note

related to https://github.com/microsoft/vscode-python/issues/6017

[DonJayamanne]

I’d block this issue, waiting for the new Debug Adapter work. Else we’ll end up doubling our work looking at issues in both debug adapters.

[karthiknadig]

We need to test this. It should not be a problem anymore, since we use the same mechanism as above to attach to multiple processes. The only thing that is concerning is that this is using integratedTerminal which is default. I am not sure how that impact will be when launching multiple processes.