4. 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.
4.1. Highlights¶
The highlights, since the 8.6.1 release, are:
- A long-standing bug exposed in GHC 8.6.1, Trac #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 (Trac #14251), resulting in incorrect floating point evaluation, has been fixed.
- Several compiler panics observed in GHC 8.6.1 have been fixed (Trac #15499, Trac #15053, Trac #15692, Trac #15695)
- GHC now runs without complaining when installed to a read-only location on Windows (Trac #15667)
- An integer overflow, resulting in some
encodeFloatuses returning incorrect results, has been fixed (Trac #15271)
4.2. 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.
4.3. 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 |