try `${PYTHON}-config --prefix`/lib for a last resort LDFLAGS for libpython (trac #149)

git-svn-id: svn://bind10.isc.org/svn/bind10/branches/trac149@1732 e5f2f494-b856-4b98-b285-d166d9295462

configure.ac

@@ -51,8 +51,19 @@ fi
 PYTHON_INCLUDES=`${PYTHON}-config --includes`
 AC_SUBST(PYTHON_INCLUDES)
 for flag in `${PYTHON}-config --ldflags`; do
-	PYTHON_LDFLAGS="$PYTHON_LDFLAGS `echo $flag | sed -ne 's/^\(\-L.*\)$/\1/p'`"
+	# add any '-L..." flags to PYTHON_INCLUDES
+	flag=`echo $flag | sed -ne 's/^\(\-L.*\)$/\1/p'`
+	if test "X${flag}" != X; then
+		PYTHON_LDFLAGS="$PYTHON_LDFLAGS ${flag}"
+	fi
 done
+# on some platforms, ${PYTHON}-config --ldflags doesn't provide a -L option
+# while having the library under a non trivial directory.  as a workaround
+# we try the "lib" sub directory under the common prefix for this python.
+if test -z "${PYTHON_LDFLAGS}"; then
+	PYTHON_LDFLAGS="-L`${PYTHON}-config --prefix`/lib"
+fi
+echo "python ldflags is ${PYTHON_LDFLAGS}."
 AC_SUBST(PYTHON_LDFLAGS)
 
 # Check for python library (not absolutely mandatory, but needed for