SYNOPSIS
dh_extra_haskell_depends [debhelper options] [-Xpackage] [--exclude=package] [file ...]DESCRIPTION
dh_haskell_extra_depends is a debhelper program that helps with calculating dependencies for building Haskell libraries.Since Haskell libraries are statically linked, packagers that use Haskell libraries cannot rely on the fact that dynamical libraries are dependencies of their packages to be sure that possible runtime data packages are installed at execution time. The extra dependencies mechanism allows libraries to declare some packages that are to be added to the dependency list of each package that uses them to build.
This script scans the Haskell dependencies and harvest extra dependencies information, putting them in the file debian/extra-depends, which is later used by dh_haskell_depends to be included in the substvars file.