[commit: ghc] ghc-7.8: One more documentation note. (7fa9d83)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : ghc-7.8
Link       : http://ghc.haskell.org/trac/ghc/changeset/7fa9d836e3b3e16d3d69a8954cf500dfaa3ea54e/ghc

>---------------------------------------------------------------

commit 7fa9d836e3b3e16d3d69a8954cf500dfaa3ea54e
Author: Austin Seipp <austin at well-typed.com>
Date:   Fri Dec 19 09:44:50 2014 -0600

    One more documentation note.
    
    Signed-off-by: Austin Seipp <austin at well-typed.com>


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7fa9d836e3b3e16d3d69a8954cf500dfaa3ea54e
 docs/users_guide/bugs.xml | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/docs/users_guide/bugs.xml b/docs/users_guide/bugs.xml
index dba0d86..8bb9772 100644
--- a/docs/users_guide/bugs.xml
+++ b/docs/users_guide/bugs.xml
@@ -466,6 +466,15 @@ checking for duplicates.  The reason for this is efficiency, pure and simple.
 
     <itemizedlist>
       <listitem>
+	<para>GHC has a bug in 7.8 that causes the new extension
+	<literal>-XAutoDeriveTypeable</literal> to not take affect -
+	however, you can easily work around this by merely using
+	<literal>-XDeriveDataTypeable</literal> and using
+	<literal>deriving Typeable</literal> instead. See GHC issue
+	#9575.</para>
+      </listitem>
+
+      <listitem>
 	<para> GHC can warn about non-exhaustive or overlapping
         patterns (see <xref linkend="options-sanity"/>), and usually
         does so correctly.  But not always.  It gets confused by