On behalf of the maintainers team I'm happy to announce that bytestring-0.11.0.0 (http://hackage.haskell.org/package/bytestring-0.11.0.0) is finally released. It is to be shipped with the upcoming GHC 9.0. Highlights from the changelog (https://github.com/haskell/bytestring/blob/0.11.0.0/Changelog.md): * Optimize internal representation of ByteString reducing allocations. * Rewrite rules for {take,drop}While, any, all, findInd{ex,ices} (an order of magnitude faster in certain cases). * Faster (up to 5%-30%) implementations of fold{l,r}, scan{l,r}, mapAccum{L,R}, any, all, filter. * Add indexMaybe and synonym (!?) for safe indexing. * Re-export Data.ByteString.Lazy.{from,to}Strict from Data.ByteString. * Remove deprecated modules and functions. Many people contributed their time and effort to make this release happen. Just to name a few in no particular order, mostly according to `git log`: * Alexandre Esteves * Andreas Klebinger * Andrew Martin * Ben Gamari * Cole Miller * Edward Kmett * Fintan Halpenny * Fumiaki Kinoshita * Hécate Kleidukos * Peter Duchovni * Sergey Vinokurov * Simon Jakobi * Sylvain Henry * Viktor Dukhovni * me Here is an incantation for `stack` folks: resolver: nightly-2020-09-23 packages: - . extra-deps: - bytestring-0.11.0.0 - github: haskell/cabal commit: 5139d6e72d391bffa3cf06f08884277799eb0b45 subdirs: - Cabal - binary-0.8.8.0 - directory-1.3.6.0 - text-1.2.3.2 - unix-2.7.2.2 - parsec-3.1.14.0 - process-1.6.9.0 allow-newer: true Best regards, Andrew