GHC 9.0.1 is now available

bgamari - 2021-02-04

The GHC team is very pleased to announce the availability of GHC 9.0.1. Source and binary distributions are available at the usual place.

In addition to numerous bug fixes, GHC 9.0.1 brings a number of new features:

  • A first cut of the new LinearTypes language extension, allowing use of linear function syntax and linear record fields.

  • A new bignum library, ghc-bignum, improving portability and allowing GHC to be more easily used with integer libraries other than GMP.

  • Improvements in code generation, resulting in considerable runtime performance improvements in some programs.

  • Improvements in pattern-match checking, allowing more precise detection of redundant cases and reduced compilation time.

  • Implementation of the “simplified subsumption” proposal simplifying the type system and paving the way for QuickLook impredicativity in GHC 9.2.

  • Implementation of the QualifiedDo extension, allowing more convenient overloading of do syntax.

  • An experimental new IO manager implementation for Windows platforms, both improving performance and fixing many of the quirks with the old manager built on POSIX-emulation.

  • Improvements in compilation time.

And many more. See the release notes for a full accounting of the changes in this release.

As always, feel free to report any issues you encounter via