[philosopher1234]

The idea is you `fmt.Errorf("invalid foo, given '%v' important argument: %w", arg, err)` and you end up with errors like:

    http GET /abc: start DB: run migration COOL_MIGRATION: invalid foo, given 'bar' important argument: file not exist

If done well, you might be able to fully diagnose the bug just by reading the error, since it may include every bit of relevant context. If not, you can grep for the original error substrings to find the relevant code.

The point is that these aren't just Xs on a map telling you where something went wrong, they're supposed to be meaningful descriptions of why something went wrong.