- Add some attach configurations to launch.json.
- Use the Debug or Configure Active options (top right of a file).
Bug: The dropdown shows duplicates (2 for Configure and 4 for Debug), which seems buggy and confusing. I'm not sure what the difference is between the duplicate options.

I hit this while investigating https://github.com/microsoft/vscode-cpptools/pull/13569 , but it was a pre-existing issue.