What goes in a Stack package.yaml file?

Question

I notice that Stack supports using a package.yaml file that it will use to generate a .cabal file. For example, yi-core/package.yaml. Its structure seems very similar to a Cabal file, but not quite the same. Some of the keys have been renamed (for example, Stack uses source-dirs instead of hs-source-dirs).

I haven't found any documentation on this feature. The Stack docs don't seem to mention package.yaml at all. Does a specification exist?

Answer 1

This is hpack, available here: https://github.com/sol/hpack

It's a slightly different package format, and, as you say, can be used to generate cabal files. It isn't directly tied to stack.