Rustpkg was deprecated and removed, but I already had a project set up to use it. This replaces rustpkg with a small Rakefile, and provides rake tasks for each crate in src.
Rakefile into the root of your rustpkg-layout directory. Run
rake -T to see a list of tasks you can run.
$ rake build:crate $ rake test:crate $ ./bin/crate
$ tree . . ├── bin │ └── crate ├── lib │ └── libcrate-abc123-0.1.rlib └── src └── crate ├── lib.rs ├── main.rs └── test.rs