The problem the reverted commit tried to fix seems to have been just a
symptom of another root cause that was later fixed as the problem does
not seem to occur anymore even without this changeset also this
changeset broke cabal sandboxes with ghc < 7.8.
Fix#262
This reverts commit 8741323f5b.
Conflicts:
Language/Haskell/GhcMod/GhcPkg.hs