7.10.3-notes.xml

<?xml version="1.0" encoding="iso-8859-1"?>
<sect1 id="release-7-10-3">
  <title>Release notes for version 7.10.3</title>

  <para>
    The 7.10.3 release is a bugfix release, with over fifty bug fixes
    relative to 7.10.2. The major fixes are listed below. For the full
    list with more detail, see the <ulink
    url="https://ghc.haskell.org/trac/ghc/milestone/7.10.3">GHC 7.10.3
    milestone</ulink> on our bug tracker.
  </para>

  <sect2>
    <title>GHC</title>

    <itemizedlist>
      <listitem>
        <para>The simplifier no longer simplifies rewrite rules.</para>
        <para>
          Starting with 7.10.2 GHC would simplify both the left- and
          right-hand-sides of rewrite rules, causing a variety of unexpected behavior.
          Simplification of the LHS resulted in various rules to fail to fire (<ulink
          url="https://ghc.haskell.org/trac/ghc/ticket/10528">Trac #10528</ulink>, in
          particular affecting the widely used <literal>text</literal> library)
          whereas rewrites of the RHS broke some of the more exotic uses of rewrite rules
          (e.g. HERMIT, <ulink url="https://ghc.haskell.org/trac/ghc/ticket/10829">Trac
          #10829).</ulink>
        </para>
      </listitem>

      <listitem>
        <para>
          A bug in the simplifier's treatment of phantom type variables in rules
          resulting in a compiler-crash has been fixed. (<ulink
          url="https://ghc.haskell.org/trac/ghc/ticket/10689">Trac #10689</ulink>).
        </para>
      </listitem>

      <listitem>
        <para>
          A simplifier bug resulting in incorrect results when comparing against
          -0.0 has been fixed (<ulink
          url="https://ghc.haskell.org/trac/ghc/ticket/9238">Trac #9238</ulink>).
        </para>
      </listitem>

      <listitem>
        <para>
          The compiler is now better able to work around platform limits on
          command-line length on Windows thanks to support for response files
          (<ulink url="https://ghc.haskell.org/trac/ghc/ticket/10375">Trac
          #10375</ulink>) and an upgrade to the GCC toolchain (<ulink
          url="https://ghc.haskell.org/trac/ghc/ticket/10726">Trac
          #10726</ulink>)
        </para>
      </listitem>

      <listitem>
        <para>
          The linker is now far less verbose when faced with certain warning conditions on Windows.
          (<ulink url="https://ghc.haskell.org/trac/ghc/ticket/9297">Trac
          #9297</ulink>).
        </para>
      </listitem>

      <listitem>
        <para>
          Framework flags are now included in the linker command line on Mac OS X
          (<ulink url="https://ghc.haskell.org/trac/ghc/ticket/10568">Trac
          #10568</ulink>).
        </para>
      </listitem>

      <listitem>
        <para>
          Compiler error messages containing Unicode characters no longer crash
          the compiler on platforms without Unicode support.
          (<ulink url="https://ghc.haskell.org/trac/ghc/ticket/6037">Trac
          #6037</ulink>).
        </para>
      </listitem>

      <listitem>
        <para>
          ARM support should be substantially more reliable as the compiler now
          takes precautions to avoid linking against Thumb code (<ulink
          url="https://ghc.haskell.org/trac/ghc/ticket/10375">Trac #10375</ulink>).
          Unfortunately the fix involved breaking some configurations. See the
          entry in the "Known Bugs" section below.
        </para>
      </listitem>

      <listitem>
        <para>
          A bug in the typechecker's treatment of
          <literal>PartialTypeSignatures</literal> which previously resulted in
          a compile-time crash has been fixed. (<ulink
          url="https://ghc.haskell.org/trac/ghc/ticket/10438">Trac #10438</ulink>).
        </para>
      </listitem>
      <listitem>
        <para>
          A typechecker bug leading to the compiler crashing has been resolved
          (<ulink url="https://ghc.haskell.org/trac/ghc/ticket/10489">Trac
          #10489</ulink>).
        </para>
      </listitem>

      <listitem>
        <para>
          Due to a <ulink url="https://ghc.haskell.org/trac/ghc/ticket/10826">
          security issue
          </ulink>, Safe Haskell now forbids annotations in programs marked as
          <literal>-XSafe</literal>
        </para>
      </listitem>

      <listitem>
        <para>
          The Template Haskell <literal>getQ</literal> and
          <literal>putQ</literal> functions are fixed (having been broken since GHC
          7.10.1, (<ulink url="https://ghc.haskell.org/trac/ghc/ticket/10596">Trac
          #10596</ulink>).
        </para>
      </listitem>
    </itemizedlist>
  </sect2>


  <sect2>
    <title>Libraries</title>

    <sect3>
        <title>base</title>
        <itemizedlist>
            <listitem>
                <para>
                    Version number 4.8.2.0 (was 4.8.1.0)
               </para>
           </listitem>
            <listitem>
                <para>
                    The <literal>GiveGCStats</literal>,
                    <literal>DoCostCentres</literal>, <literal>DoHeapProfile</literal>,
                    <literal>DoTrace</literal>, <literal>Time</literal>, and <literal>Nat</literal>
                    datatypes are now exported from
                    <literal>GHC.RTS.Flags</literal>.
                </para>
           </listitem>
       </itemizedlist>
    </sect3>
  </sect2>

  <sect2>
    <title>Known bugs</title>
    <itemizedlist>
      <listitem>
        <para>
          Unfortunately the fix for
          <ulink url="https://ghc.haskell.org/trac/ghc/ticket/10375">Trac #10375</ulink>
          required that support for the ARM Thumb instruction set be disabled.
          See <ulink url="https://ghc.haskell.org/trac/ghc/ticket/11058">Trac
          #11058</ulink> for details.
        </para>
      </listitem>
   </itemizedlist>
  </sect2>
</sect1>