[AC_MSG_RESULT([checking for Boost system library... yes])],
[AC_MSG_RESULT([checking for Boost system library... yes])],
[AC_MSG_RESULT([checking for Boost system library... no])
[if test "x${BOOST_LIB_DIR}" = "x"; then
AC_MSG_ERROR([Linking with ${BOOST_LIBS} is not enough: please make sure libboost_system is installed; Check config.log for details, you may be missing other libraries.])])
[AC_MSG_RESULT([checking for Boost system library... yes])],
[AC_MSG_RESULT([checking for Boost system library... no])
AC_MSG_ERROR([Linking with ${BOOST_LIBS} is not enough: please make sure libboost_system is installed in an expected location; Check config.log for details, you may be missing other libraries.])])])