.. _release-8-6-2: Release notes for version 8.6.2 =============================== GHC 8.6.2 is a bug-fix release, fixing a few regressions found in 8.6.1. Highlights ---------- The highlights, since the 8.6.1 release, are: - A long-standing bug exposed in GHC 8.6.1, :ghc-ticket:`15696`, has been fixed. This issue resulted in undefined runtime behavior with some uses of the ``dataToTag#`` primop. Note that this issue, while less likely to manifest, has existed in some form in all GHC releases prior to this release and may result in silent, incorrect evaluation. For this reason, users are strongly encouraged to upgrade to 8.6.2. - A long-standing bug in the LLVM code generator (:ghc-ticket:`14251`), resulting in incorrect floating point evaluation, has been fixed. - Several compiler panics observed in GHC 8.6.1 have been fixed (:ghc-ticket:`15499`, :ghc-ticket:`15053`, :ghc-ticket:`15692`, :ghc-ticket:`15695`) - GHC now runs without complaining when installed to a read-only location on Windows (:ghc-ticket:`15667`) - An integer overflow, resulting in some ``encodeFloat`` uses returning incorrect results, has been fixed (:ghc-ticket:`15271`) Known issues ------------ Note that the LLVM code generator (:ghc-flag:`-fllvm`) in GHC 8.6, as well as all earlier releases, are affected by :ghc-ticket:`14251`, which can result in miscompilation of some programs calling functions with unboxed floating-point arguments. While originally scheduled to be fixed for this release, the fix ended up being more difficult than anticipated and, given that issue is not a strict regression from 8.4, we decided to proceed with the release. 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. .. ghc-package-list:: libraries/array/array.cabal: Dependency of ``ghc`` library libraries/base/base.cabal: Core library libraries/binary/binary.cabal: Dependency of ``ghc`` library libraries/bytestring/bytestring.cabal: Deppendency of ``ghc`` library libraries/Cabal/Cabal/Cabal.cabal: Dependency of ``ghc-pkg`` utility libraries/containers/containers.cabal: Dependency of ``ghc`` library libraries/deepseq/deepseq.cabal: Dependency of ``ghc`` library libraries/directory/directory.cabal: Dependency of ``ghc`` library libraries/filepath/filepath.cabal: Dependency of ``ghc`` library compiler/ghc.cabal: The compiler itself libraries/ghci/ghci.cabal: The REPL interface libraries/ghc-boot/ghc-boot.cabal: Internal compiler library libraries/ghc-compact/ghc-compact.cabal: Core library libraries/ghc-prim/ghc-prim.cabal: Core library libraries/haskeline/haskeline.cabal: Dependency of ``ghci`` executable libraries/hpc/hpc.cabal: Dependency of ``hpc`` executable libraries/integer-gmp/integer-gmp.cabal: Core library libraries/mtl/mtl.cabal: Dependency of ``Cabal`` library libraries/parsec/parsec.cabal: Dependency of ``Cabal`` library libraries/process/process.cabal: Dependency of ``ghc`` library libraries/template-haskell/template-haskell.cabal: Core library libraries/text/text.cabal: Dependency of ``Cabal`` library libraries/time/time.cabal: Dependency of ``ghc`` library libraries/transformers/transformers.cabal: Dependency of ``ghc`` library libraries/unix/unix.cabal: Dependency of ``ghc`` library libraries/Win32/Win32.cabal: Dependency of ``ghc`` library libraries/xhtml/xhtml.cabal: Dependency of ``haddock`` executable