Support code for reading and manipulating hashed file storage (where
each file and directory is associated with a cryptographic hash, for
corruption-resistant storage and fast comparisons).

The supported storage formats include darcs hashed pristine, a plain
filesystem tree and an indexed plain tree (where the index maintains
hashes of the plain files and directories).

This requires ghc, haskell-binary, haskell-dataenc, haskell-mmap,
haskell-transformers, haskell-zlib, and haskell-mtl.

After uninstalling, run this command to unregister the package from
the ghc package database:   ghc-pkg recache