[tavert]

"proper package" in that it has a toml file and a uuid, but it can't be controlled by the package manager in terms of updating, handling installation, or pinning versions. The stdlib "packages" are an awkward in-between state that isn't usable the way a full package would be, the only thing it has forced people to do relative to being included in Base is now you need to do `using LinearAlgebra` to load it in downstream code. That might get fixed eventually so you can express that you depend on the LinearAlgebra 1.0 API to isolate yourself from stdlib breakage, but there's no way to do that today short of doing the work yourself to create a full versioned package with the same content.