[commit: ghc] master: configure.ac: fix --host= handling (0cc3931)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/0cc3931bd7831fa8d042f968a5a9114534a656e4/ghc

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

commit 0cc3931bd7831fa8d042f968a5a9114534a656e4
Author: Sergei Trofimovich <slyfox at gentoo.org>
Date:   Fri Sep 2 08:35:25 2016 +0100

    configure.ac: fix --host= handling
    
    The following command fails as:
        $ ./configure --prefix=/usr \
            --build=x86_64-pc-linux-gnu \
            --host=x86_64-pc-linux-gnu \
            --target=x86_64-pc-linux-gnu
        configure: error:
        You've selected:
    
          BUILD:  x86_64-unknown-linux
          HOST:   x86_64-unknown-linux
          TARGET: x86_64-unknown-linux
    
        BUILD must equal HOST;
    
    18f06878ed5d8cb0cf366a876f2bfea29647e5f0 changed native
    configure $build/$host/$target checks to ghc-mangled ones,
    but not completely.
    
    Signed-off-by: Sergei Trofimovich <siarheit at google.com>
    
    Reviewers: rwbarton, erikd, austin, hvr, bgamari, Phyx
    
    Reviewed By: Phyx
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D2508
    
    GHC Trac Issues: #12487


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

0cc3931bd7831fa8d042f968a5a9114534a656e4
 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index ea3ba4e..0fceb16 100644
--- a/configure.ac
+++ b/configure.ac
@@ -417,7 +417,7 @@ if test "$TargetPlatform" != "$HostPlatform" ; then
                           #   configure: error: cannot run C compiled programs.
                           #   If you meant to cross compile, use `--host'.
 fi
-if test "$BuildPlatform" != "$host" ; then
+if test "$BuildPlatform" != "$HostPlatform" ; then
    AC_MSG_ERROR([
 You've selected: