Proposal

Because you liked my first suggestion, I took the liberty of suggesting some more changes to simplify readability. Hope they are welcome and I'd love to hear what you think of them. I also hope I didn't break anything :100: 
>rename it to resolvePath and describe the function in its documentation, or
>remove it from here and declare it inline where it is currently used - which would be a bit more like your implementation, unless you see any stylistic problems with this approach.

I think it's simpler to put it back inside Start

> Have also read somewhere that it's not recommended to panic inside a package, but rather give control to the user. With that in mind I was thinking to return that error via a secondary return value on Start , rather than dropping Fatalf

This is a deliberate choice, it was important to me to keep the single line usage of this package.