This library is deprecated because its functionality has been merged into the core what4 library.
This library provided a mechanism to serialize what4 terms into an s-expression format (and later deserialize them).
The dependencies of the project that are not on Hackage are specified using git submodules. To build the code with a modern version of cabal
(assuming you are in the root of the repository):
$ git submodule update --init
$ ln -s cabal.project.newbuild cabal.project
$ cabal new-configure
$ cabal new-build what4-serialize