AC_ARG_ENABLE(mcs-build, [ --disable-mcs-build disable the build of the mcs directory], try_mcs_build=$enableval, enable_mcs_build=yes)
AC_ARG_WITH(xen_opt, [ --with-xen_opt=yes,no Enable Xen-specific behaviour (defaults to yes)],[],[with_xen_opt=yes])
AC_ARG_ENABLE(mcs-build, [ --disable-mcs-build disable the build of the mcs directory], try_mcs_build=$enableval, enable_mcs_build=yes)
AC_ARG_WITH(xen_opt, [ --with-xen_opt=yes,no Enable Xen-specific behaviour (defaults to yes)],[],[with_xen_opt=yes])