问题
Stack allows global installation of packages using stack install <packagename> outside of a project directory.
Stack also has a ~/.stack/global-project/stack.yaml file that allows configuration of the global-project. However I can't see a way to "install" packages declaratively. The extra-deps and packages key in the yaml file don't seem to work for this method.
Instead I just have to run stack install <...> <...> each time the snapshot version gets updated for my global-project.
来源：https://stackoverflow.com/questions/47989939/is-there-a-declarative-way-to-specify-packages-to-be-installed-into-global-proje