Use VS Code to debug a go program that is running externally

build-and-launch-dlv.bash

# see also https://github.com/go-delve/delve/tree/master/Documentation/api/dap
go build -o plaintweet-darwin \
&& dlv exec --headless --log --api-version 2 --listen localhost:42353 -- ./plaintweet-darwin serve

launch.json

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Attach to Process",
      "type": "go",
      "request": "attach",
      "mode": "remote",
      "apiVersion": 2,
      "port": 42353
    },
  ]
}

For vim, this would be :GoDebugConnect :42353

see Vim, Go and Remote Debugging