ghc-7.8.4-41.fc22
Oh dear - gcc5 changes all the ghc library ABI hashes.
Sorry my initial hunch seems incorrect. AFAICT now the ABI changes are due to -40 having been built with make -j16 on i686 and x86_64.
In future I will use -j4 or less again.
Jens
haskell@lists.fedoraproject.org