VSCode

Create a file .vscode/launch.json in your project root folder and add this content:

{
  "version": "0.2.0",
  "configurations": [
      {
          "name": "Launch",
          "type": "go",
          "request": "launch",
          "mode": "auto",
          "program": "${workspaceFolder}",
          "env": {"Foo":"bar"},
          "args": ["foo bar"],
          "cwd": "${workspaceRoot}"
      }
  ]
}