.. _release-9-6-4: Version 9.6.4 ============== The significant changes to the various parts of the compiler are listed below. See the `migration guide <https://gitlab.haskell.org/ghc/ghc/-/wikis/migration/9.6>`_ on the GHC Wiki for specific guidance on migrating programs to this release. The :ghc-flag:`LLVM backend <-fllvm>` of this release is to be used with LLVM 11, 12, 13, 14 or 15. Significant Changes ~~~~~~~~~~~~~~~~~~~~ Issues fixed in this release include: Compiler -------- - Fix a code generator bug on AArch64 platforms resulting in invalid conditional jumps (:ghc-ticket:`23746`). - Fix a simplifier bug that may cause segfaults and core lint failures due to incorrect handling of join points (:ghc-ticket:`23952`). - Ensure unconstrained instance dictionaries get IPE info (:ghc-ticket:`24005`). - Fix a bug where we could silently truncate 64 bit values to 32 bit on 32 bit architectures. - Fix a GHCi bug where a failure in the ``:add`` command would cause the process to exit (:ghc-ticket:`24115`). - Fix a bug causing suboptimal error messages for certain invalid cyclic module graphs with hs-boot files (:ghc-ticket:`24196`). - Fix a bug causing compiler panics with certain package databases involving unusable units and module reexports (:ghc-ticket:`21097`, :ghc-ticket:`16996`, :ghc-ticket:`11050`). - Fix some memory leaks in GHCi that manifest on reloads (:ghc-ticket:`24107`, :ghc-ticket:`24118`). - Fix a bug leading to some template haskell splices failing on being reloaded into GHCi due to not clearing the interactive context properly (:ghc-ticket:`23405`). - Fix a type checker crash on certain programs involving implicitly scoped type variables (:ghc-ticket:`24083`). - Fix a bug where certain warning flags were not recognised (:ghc-ticket:`24071`). - Fix an incorrect assertion in the simplifier (:ghc-ticket:`23862`). - Align objects in the data section properly when using the LLVM backend (:ghc-ticket:`24163`). Runtime system -------------- - Ensure concurrent thunk update is sound (:ghc-ticket:`23185`). - Ensure the ``listAllBlocks`` function takes the non-moving heap into account (:ghc-ticket:`22627`). - Ensure the non-moving GC is not running when pausing - Fix some non-moving loops and bugs on Windows and LLP64 platforms (:ghc-ticket:`23003`, :ghc-ticket:`24042`). - Fix a bug where certain programs could have incorrect async exception masking (:ghc-ticket:`23513`). - Ensure we respect maximum event length and don't overflow into program memory (:ghc-ticket:`24197`). Build system and packaging -------------------------- - Ensure we use the right linker flags on AArch64 darwin (:ghc-ticket:`21712`, :ghc-ticket:`24033`). - Fix a bug where ``-DNOSMP`` wasn't being passed to the C compiler even if the target doesn't support SMP (:ghc-ticket:`24082`). - Ensure we use the right ``otool`` and ``install_name_tool`` on Darwin (:ghc-ticket:`24211`). Core libraries -------------- - Fix a bug in ghc-bignum where usage of `bigNatIsPowerOf2` might result in out of bounds access (:ghc-ticket:`24066`). - Bump ``base`` to 4.18.2.0 - base: Update to Unicode 15.1.0 - Bump ``filepath`` to 1.4.200.1 - Bump ``unix`` to 2.8.4.0 - Bump ``haddock`` to 2.29.2 - Bump ``bytestring`` to 0.11.5.3 Included libraries ------------------ The package database provided with this distribution also contains a number of packages other than GHC itself. See the changelogs provided with these packages for further change information.