x11-themes/alloy depends on kdebase-meta instead of kwin. That means that you are prompted to install the whole kdebase-meta pack, incl. dependencies, if you want to emerge alloy, which is not needed. Reproducible: Always Steps to Reproduce: emerge -pv alloy I think the dep could be changed to || (kwin kdebase), like in x11-themes/qinx.
corrected