Hello everyone, The GHC development team is very pleased to announce the first beta leading up to GHC 8.6.1 release. The usual release artifacts are available from https://downloads.haskell.org/~ghc/8.6.1-beta1 This beta fixes most of the bugs reported in the first two alphas and brings all of the core libraries up to their final release versions. The 8.6 release fixes over 300 bugs from the 8.4 series and introduces a number of exciting features. These most notably include: * Significantly better handling of macOS linker command size limits, avoiding linker errors while linking large projects * A new deriving mechanism, `deriving via`, providing a convenient way for users to extend Haskell's typeclass deriving mechanism * Quantified constraints, allowing forall quantification in contexts * An early version of the GHCi `:doc` command * The `ghc-heap-view` package, allowing introspection into the structure of GHC's heap * Valid hole fit hints, helping the user to find terms to fill typed holes in their programs * The BlockArguments extension, allowing the `$` operator to be omitted in some unambiguous contexts * The next phase of the MonadFail proposal, enabling -XMonadFailDesugaring by default A full list of the changes in this release can be found in the release notes: https://downloads.haskell.org/~ghc/8.6.1-beta1/docs/html/users_guide/8.6.1-n... This will very likely be the last release before the final 8.6.1 so do give it a thorough testing and, as always, report any issues you encounter. Thanks for your help! Cheers, - Ben