Apparently haddock-library needs to be included for GHC 7.8.4 as well as for GHC 7.10. When building 4.2.6 I get the message below while 4.2.5 builds fine.
src/haddock-api/Haskell/Docs/HaddockDoc.hs:14:18:
Could not find module ‘Documentation.Haddock.Types’
It is a member of the hidden package ‘haddock-library-1.1.1’.
Perhaps you need to add ‘haddock-library’ to the build-depends in your .cabal file.
Apparently haddock-library needs to be included for GHC 7.8.4 as well as for GHC 7.10. When building 4.2.6 I get the message below while 4.2.5 builds fine.