https://bugzilla.redhat.com/show_bug.cgi?id=973512
--- Comment #6 from Jens Petersen petersen@redhat.com --- (In reply to Jens Petersen from comment #2)
https://github.com/ghc/ghc/commit/08a38628f29df63ac842f4d083efb414f42d7bff which I backported to rawhide in ghc-7.6.3-15.fc20.
Unfortunately even with ghc-7.6.3-15.fc20 executables still seems to get executable stack... It also changed the ABI hash of the ghc library. :-(
For now I added a workaround to ghc-rpm-macros to clear the execstack flag when building Fedora Haskell packages, but leaving this open until the actual problem in ghc is fixed.