I’ve made a new release of Hpack-Dhall, hpack-dhall-0.6.0. Hpack-Dhall is like Hpack but with the “functions + types + imports” of Dhall. There’s a new user guide at Hpack⩓Dhall and this release adds cabal ypack and cabal dpack Cabal external commands.
Stack has Hpack builtin. If any of a project’s .cabal files don’t exist or are out of date for any package.yaml file then Stack will arrange with Hpack to generate the package description in .cabal format before proceeding with the build or other command that requires a .cabal file for a package.
A little more explicit but just as capable is cabal ypack. This will create .cabal files for any package.yaml files in the project tree. This is a low effort way to have Hpack in your Cabal project without needing Stack there too or something like a Makefile or Shake rule.
My favorite new command is cabal dpack that will create a .cabal file for any package.dhall file in the project tree.