mimics the duplication of strings in `Builder` for `Pkg`. This ensures the lifetime of the memory backing strings in a `Pkg` struct and the `Pkg.dependencies` slice is not shorter than the `Builder` that the data is associated with.
mimics the duplication of strings in `Builder` for `Pkg`. This ensures the lifetime of the memory backing strings in a `Pkg` struct and the `Pkg.dependencies` slice is not shorter than the `Builder` that the data is associated with.