Merge fast and break things

[jonringer]

@lilyball

I wonder if we could do something helpful here like having the built-in fetchers expose a helper method that can be called to provide a default name if one was not given to the fetcher in the first place. Then mkDerivation could just call that on its src (or srcs ) to provide its name if the package source did not already provide a name.

I already started on this front: [staging] fetchFromGitHub: name source with content intristic to the value by jonringer · Pull Request #153386 · NixOS/nixpkgs · GitHub