1.5. Release notes for version 6.12.2

The significant changes to the various parts of the compiler are listed in the following sections. There have also been numerous bug fixes and performance improvements over the 6.10 branch.

1.5.1. Compiler and Runtime system

  • A new flag -no-rtsopts flag allows you to disable parsing of +RTS ... options by the run-time system.

    In some use-cases, when a program can be run as another user, this can cause security problems. For example, myprog -tsomefile will overwrite somefile if the other user has permissions to do so.

  • The mingw installation bundled with GHC on Windows now includes a C++ compiler again.

  • Support for the FreeBSD, Dragonfly and Haiku OSes has been improved.

  • Datatypes with a context but no constructors, e.g.

    data Show a => T a

    are accepted again.

  • Importing qualified names is now an error.

  • ghc-pkg now ensures that the conf files it writes are UTF8.

1.5.2. Template Haskell

  • A bug in the kind parser has been fixed.

1.5.3. Libraries array

  • No change; version base

  • Version number (was bytestring

  • Version number (was Cabal

  • Version number (was

  • Distribution.ModuleName.simple has been deprecated; use Distribution.ModuleName.fromString instead. containers

  • No change; version directory

  • Version number (was

  • System.Directory.doesFileExist on Unix-like OSes now correctly identifies various types of special file as files.  dph (dph-base, dph-par, dph-prim-interface, dph-prim-par, dph-prim-seq, dph-seq)

  • All the dph packages are version 0.4.0. extensible-exceptions

  • No change; version filepath

  • Version number (was ghc-binary

  • This is an internal package, and should not be used. ghc-prim

  • No change; version haskell98

  • No change; version hpc

  • Version number (was integer-gmp

  • Version number (was integer-simple

  • No change; version old-locale

  • No change; version old-time

  • Version number (was pretty

  • No change; version process

  • No change; version random

  • No change; version syb

  • No change; version template-haskell

  • Version number (was time

  • No change; version 1.1.4. unix

  • Version number (was Win32

  • Version number (was