diff -up ./graphviz-2.28.0/configure.xorig ./graphviz-2.28.0/configure
--- graphviz-2.28.0/configure.xorig	2011-05-07 05:27:36.000000000 +0200
+++ graphviz-2.28.0/configure	2011-05-19 13:45:26.026395747 +0200
@@ -20066,7 +20066,7 @@ fi
       if test "x$GUILE" = "x"; then
         use_guile="No (guile not available)"
       else
-        GUILE_VERSION=`$GUILE --version | head -1 | cut -d ' ' -f 2`
+        GUILE_VERSION=`$GUILE --version | sed -n '1 s/^.* \+\([0-9\.]\+\)$/\1/ p'`
         GUILE_VERSION_MAJOR=`echo $GUILE_VERSION | cut -d '.' -f 1`
         GUILE_VERSION_MINOR=`echo $GUILE_VERSION | cut -d '.' -f 2`
         if test $GUILE_VERSION_MAJOR -lt 2; then
@@ -20081,9 +20081,16 @@ fi
         if test "x$GUILE" = "x"; then
 	  use_guile="No (guile is too old)"
         else
-          GUILE_INCLUDES=
-          GUILE_LIBS=
+          GUILE_INCLUDES=`$PKG_CONFIG --cflags "guile-$GUILE_VERSION_MAJOR.$GUILE_VERSION_MINOR" 2>/dev/null`
+          GUILE_LIBS=`$PKG_CONFIG --libs "guile-$GUILE_VERSION_MAJOR.$GUILE_VERSION_MINOR" 2>/dev/null`
+
+          ac_save_CFLAGS="$CFLAGS"
+          ac_save_CPPFLAGS="$CPPFLAGS"
+          CFLAGS="$CFLAGS $GUILE_INCLUDES"
+          CPPFLAGS="$CPPFLAGS $GUILE_INCLUDES"
           ac_fn_c_check_header_mongrel "$LINENO" "libguile.h" "ac_cv_header_libguile_h" "$ac_includes_default"
+          CFLAGS="$ac_save_CFLAGS"
+          CPPFLAGS="$ac_save_CPPFLAGS"
 if test "x$ac_cv_header_libguile_h" = x""yes; then :
 
 else