6. Release notes for version 8.6.4

GHC 8.6.4 is a bug-fix release, fixing a few regressions found in 8.6.3.

6.1. Highlights

The highlights, since the 8.6.3 release, are:

  • Inconsistencies between the versions of transformers and process shipped with the compiler and those present on Hackage have been resolved (Trac #16199).

  • A patch fixing a set of linker failures on Windows has been reverted as it unfortunately caused (Trac #15105, Trac #15894, Trac #15934)

  • A bug wherein changes in default method definitions would fail to trigger recompilation has been fixed (Trac #15970).

  • A bug wherein plugins would fail to lookup names not in scope in the module being compiled has been fixed (Trac #16104)

  • A bug resulting in hangs during RTS shutdown on Darwin has been resolved (Trac #16150)

  • A bug where some programs involving StaticData would be rejected with either a typechecking error or internal compiler error has been fixed (Trac #16141)

  • A bug where compilation on Windows can fail with linker errors referring to __chkstk_ms has been fixed (Trac #16166)

6.2. Known issues

Note that the LLVM code generator (-fllvm) in GHC 8.6, as well as all earlier releases, are affected by Trac #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.

6.3. 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.

Package Version Reason for inclusion

ghc

8.6.5

The compiler itself

Cabal

2.4.0.1

Dependency of ghc-pkg utility

Win32

2.6.1.0

Dependency of ghc library

array

0.5.3.0

Dependency of ghc library

base

4.12.0.0

Core library

binary

0.8.6.0

Dependency of ghc library

bytestring

0.10.8.2

Deppendency of ghc library

containers

0.6.0.1

Dependency of ghc library

deepseq

1.4.4.0

Dependency of ghc library

directory

1.3.3.0

Dependency of ghc library

filepath

1.4.2.1

Dependency of ghc library

ghc-boot

8.6.5

Internal compiler library

ghc-compact

0.1.0.0

Core library

ghc-prim

0.5.3

Core library

ghci

8.6.5

The REPL interface

haskeline

0.7.4.3

Dependency of ghci executable

hpc

0.6.0.3

Dependency of hpc executable

integer-gmp

1.0.2.0

Core library

mtl

2.2.2

Dependency of Cabal library

parsec

3.1.13.0

Dependency of Cabal library

process

1.6.5.0

Dependency of ghc library

template-haskell

2.14.0.0

Core library

text

1.2.3.1

Dependency of Cabal library

time

1.8.0.2

Dependency of ghc library

transformers

0.5.6.2

Dependency of ghc library

unix

2.7.2.2

Dependency of ghc library

xhtml

3000.2.2.1

Dependency of haddock executable