[gentoo-catalyst] are sets supported with catalyst as value for stage4/packages: ?

[lin pro]

Hi,
I populated portage_confdir with a sets directory and astronomy file with:
eix --only-names -C sci-astronomy >> astronomy

Now catalyst, when run, says the set does not exist which means that
emerge cannot see it.
What can be done to satisfy emerge in that respect?

Thank you for any answers
Ben

-- 
best regards
linforpros