Install libghc-servant-doc by entering the following commands in the terminal:
sudo apt update sudo apt install libghc-servant-doc
Description:
family of combinators for defining webservices APIs; documentation
A family of combinators for defining webservices APIs and serving them. . This package provides the documentation for a library for the Haskell programming language. See http://www.haskell.org/ for more information on Haskell.
Homepage: http://haskell-servant.readthedocs.org/
Version: 0.11-3
Section: universe/doc