disabling rpm fetch

[Elan Ruusamäe]

how do you disable rpm from fetching sources?
from build/parsePrep.c i see such macros, but defining them to %{nil}
had no effect.

if (sp->flags & RPMFILE_SOURCE) {
Rmacro = "%{?_Rsourcedir}/";
} else
if (sp->flags & RPMFILE_PATCH) {
Rmacro = "%{?_Rpatchdir}/";
} else
if (sp->flags & RPMFILE_ICON) {
Rmacro = "%{?_Ricondir}/";
} else
continue;