niminit/config/templates/nim/launch.json

{
    "version": "0.2.0",
    "configurations": [
        {
            "type": "lldb",
            "request": "launch",
            "name": "nim: debug current file",
            "preLaunchTask": "nim: build current file (for debugging)",
            "program": "${workspaceFolder}/bin/${fileBasenameNoExtension}",
            "args": [],
            "cwd": "${workspaceFolder}"
        }
    ]
}