Could you please add an option to make this path.join optional?

The reason is that I would like to deploy a folder built with Nix. When Nix builds something, the output lands in a central store under /nix/store and the output which gets placed in the current directory is a symlink to the store location. Since the build_dir option needs a relative path, I end up having to work around this problem by prepending it with ../../../../../, which is kind of ugly. It works for now, but I would prefer to be able to provide an absolute path (or even better, just be able to provide the symlink, but that doesn't seem to work because the copy function doesn't want to overwrite a folder with a symlink).

Thanks!