AC_CHECK_HEADERS([libconfig.h], [], [AC_MSG_ERROR([could not find libconfig.h])])
AC_CHECK_LIB([config], [config_init], [], [AC_MSG_ERROR([could not find libconfig])])
case $host_os in
AC_CHECK_HEADERS([libconfig.h], [], [AC_MSG_ERROR([could not find libconfig.h])])
AC_CHECK_LIB([config], [config_init], [], [AC_MSG_ERROR([could not find libconfig])])
case $host_os in