6.8.2 is a bugfix release over 6.8.1. Many bugs in the compiler, libraries and build system have been fixed. However, most library APIs have not changed, so code that worked with 6.8.1 should continue to work with 6.8.2. The notable exceptions, as well as the user interface changes, are listed below.
The --print-docdir for GHC has been removed,
as there were some problems with the implementation. We'll
revisit this area in a future release.
Standalone deriving declarations now respect scope: You can't
derive a Show instance, for example, unless
all the constructors are in scope.
GHCi now treats all input as unicode, except for the Windows console where we do the correct conversion from the current code page.
In GHCi, ":" now repeats the last command.
In GHCi, :{ ..lines.. :} can be used to
give multi-line commands. This is mainly useful in
.ghci files.
In GHCi, :show languages shows the
active language extensions and :show packages
shows the loaded packages.
In GHCi, :def! now overwrites a previous
command with the same name, :def on its own
lists the defined macros, and :undef f g
undefines both f and g.
There is now a variant, :browse!,
of :browse.
Various changes have been made to GHC's internals, so there are
some differences in the API exposed by the ghc package. Most
notably, checkAndLoadModule has now been
implemented.
The version of base has been increased from 3.0.0.0 to 3.0.1.0.
The version of Cabal has been increased from 1.2.2.0 to 1.2.3.0.
The version of containers has been increased from 0.1.0.0 to 0.1.0.1.
The version of unix has been increased from 2.2.0.0 to 2.3.0.0.
The version of Win32 has been increased from 2.1.0.0 to 2.1.1.0.