Attach-type debugging fails to display process picker if no file is open (isfs workspace)

Type: Bug

Have this workspace definition (alter URL to suit your local setup):

{
    "folders": [
        {
            "name": "irislatest:USER",
            "uri": "isfs://irislatest:user/"
        }
    ],
    "launch": {
        "version": "0.2.0",
        "configurations": [

            {
                "type": "objectscript",
                "request": "launch",
                "name": "XDebug"
            },
            {
                "type": "objectscript",
                "request": "attach",
                "name": "Attach"
            }
        ]
    }
}

Open the workspace.
Make sure no documents are open.
Go to Run and Debug view, choose Attach (workspace) on the dropdown and click the Start Debugging button.

:bug: instead of the expected process picker quickpick, a modal error messagebox appears:

Extension version: 2.12.7-beta.3 VS Code version: Code 1.91.1 (f1e16e1e6214d7c44d078b1f0607b2388f29d729, 2024-07-09T22:06:49.809Z) OS version: Windows_NT x64 10.0.22631 Modes:

intersystems-community / vscode-objectscript

Attach-type debugging fails to display process picker if no file is open (isfs workspace) #1411