>From 935cab2f2c4a5764dbb865f8795105257c219af0 Mon Sep 17 00:00:00 2001
From: Jaap Eldering <address@hidden>
Date: Wed, 11 Aug 2010 15:07:21 +0200
Subject: [PATCH] On x86_64 architecture search both lib64 and lib dirs.

---
 m4/ax_boost_base.m4 |   23 ++++++++++++++++++-----
 1 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/m4/ax_boost_base.m4 b/m4/ax_boost_base.m4
index d8f063c..c0453d7 100644
--- a/m4/ax_boost_base.m4
+++ b/m4/ax_boost_base.m4
@@ -84,9 +84,14 @@ if test "x$want_boost" = "xyes"; then
     AC_MSG_CHECKING(for boostlib >= $boost_lib_version_req)
     succeeded=no
 
-    libsubdir="lib"
+    dnl On x86_64 systems check for system libraries in both lib64 and lib.
+    dnl The former is specified by FHS, but e.g. Debian does not adhere to
+    dnl this (as it rises problems for generic multi-arch support).
+    dnl The last entry in the list is chosen by default when no libraries
+    dnl are found, e.g. when only header-only libraries are installed!
+    libsubdirs="lib"
     if test "$(uname -m)" = "x86_64"; then
-        libsubdir="lib64"
+        libsubdirs="lib64 lib lib64"
     fi
 
     dnl first we check the system location for boost libraries
@@ -98,6 +103,9 @@ if test "x$want_boost" = "xyes"; then
     elif test "$cross_compiling" != yes; then
         for ac_boost_path_tmp in /usr /usr/local /opt /opt/local ; do
             if test -d "$ac_boost_path_tmp/include/boost" && test -r "$ac_boost_path_tmp/include/boost"; then
+                for libsubdir in $libsubdirs ; do
+                    if ls "$ac_boost_path_tmp/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
+                done
                 BOOST_LDFLAGS="-L$ac_boost_path_tmp/$libsubdir"
                 BOOST_CPPFLAGS="-I$ac_boost_path_tmp/include"
                 break;
@@ -172,13 +180,18 @@ if test "x$want_boost" = "xyes"; then
 
                 VERSION_UNDERSCORE=`echo $_version | sed 's/\./_/'`
                 BOOST_CPPFLAGS="-I$best_path/include/boost-$VERSION_UNDERSCORE"
-                if test "$ac_boost_lib_path" = ""
-                then
-                   BOOST_LDFLAGS="-L$best_path/$libsubdir"
+                if test "$ac_boost_lib_path" = ""; then
+                    for libsubdir in $libsubdirs ; do
+                        if ls "$best_path/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
+                    done
+                    BOOST_LDFLAGS="-L$best_path/$libsubdir"
                 fi
             fi
 
             if test "x$BOOST_ROOT" != "x"; then
+                for libsubdir in $libsubdirs ; do
+                    if ls "$BOOST_ROOT/stage/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
+                done
                 if test -d "$BOOST_ROOT" && test -r "$BOOST_ROOT" && test -d "$BOOST_ROOT/stage/$libsubdir" && test -r "$BOOST_ROOT/stage/$libsubdir"; then
                     version_dir=`expr //$BOOST_ROOT : '.*/\(.*\)'`
                     stage_version=`echo $version_dir | sed 's/boost_//' | sed 's/_/./g'`
-- 
1.5.6.5