The following libraries seem not used by any other packages and are missing from Stackage LTS 12:

ghc-HSH
ghc-IOSpec
ghc-IfElse
ghc-MonadCatchIO-mtl
ghc-MonadCatchIO-transformers
ghc-Stream
ghc-arrows
ghc-attempt
ghc-attoparsec-enumerator
ghc-aws
(ghc-bdcs)
(ghc-bdcs-api)
ghc-blaze-builder-enumerator
ghc-bloomfilter
ghc-bytestring-nums
ghc-bytestring-show
ghc-bytestring-trie
ghc-cabal-file-th
ghc-cabal-helper
ghc-cautious-file
ghc-chalmers-lava2000
ghc-cmark
ghc-concatenative
(ghc-content-store)
ghc-dataenc
ghc-date-cache
ghc-derive
ghc-djinn-ghc
ghc-djinn-lib
ghc-dotgen
ghc-enumerator
ghc-esqueleto
ghc-failure
ghc-fdo-notify
ghc-ghc-mtl
ghc-ghc-syb-utils
ghc-gi-ggit
ghc-gi-ostree
ghc-gtksourceview2
ghc-lazysmallcheck
ghc-maccatcher
ghc-magic
ghc-mtlparse
ghc-netlist
ghc-netlist-to-vhdl
ghc-publicsuffixlist
ghc-ranges
ghc-readline
ghc-regexpr
ghc-servant-options
ghc-show
ghc-torrent
ghc-wl-pprint
ghc-zlib-enum

We could probably drop some of them from Fedora.

Jens