Install libghc-hpack-doc by entering the following commands in the terminal:
sudo apt update sudo apt install libghc-hpack-doc
Description:
alternative format for Haskell packages; documentation
hpack is a tool to create the usual Haskell packaging metadata, i.e. the .cabal file, from a YAML description of the program, with some fields field in by inferred defaults and other additional conveniences. . This package provides the documentation for a library for the Haskell programming language. See http://www.haskell.org/ for more information on Haskell.
Homepage: https://github.com/sol/hpack#readme
Version: 0.18.1-1build2
Section: universe/doc