The Fedora Haskell packages have been updated to ghc-8.4.4 and Stackage LTS 12 versions, with focus on performance, stability, consolidation, and numerous cleanups throughout the compiler:
Further refinement of TypeInType, including significant improvements in error messages.
Improvements in code generation resulting in noticable performance improvements in some types of programs.
Core library improvements, including phase 2 of the Semigroup/Monoid proposal.
Many improvements to instance deriving.
The resolution of nearly 300 other tickets for the 8.4.1 major release, and further bugfixes in the subsequent stable minor version releases.
For details, see upstream release announcements:
Want to help? Learn how to contribute to Fedora Docs ›