6. Release notes for version 8.6.4 — Glasgow Haskell Compiler 8.6.4 User's Guide

# Glasgow Haskell Compiler User's Guide

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# 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 | 8.6.4 | 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 | 8.6.4 | Internal compiler library
ghc-compact | 0.1.0.0 | Core library
ghc-prim | 0.5.3 | Core library
ghci | 8.6.4 | 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

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