betelgeuse@pena /usr/portage/kde-base $ ls plasma ChangeLog CVS/ files/ Manifest metadata.xml If a dev tries to rm all the ebuilds repoman should not allow it. Portage 2.2_rc12 (default/linux/x86/2008.0/desktop, gcc-4.3.2, glibc-2.8_p20080602-r0, 2.6.27-gentoo i686)
Technically, a package directory without ebuilds is valid: "A package directory contains the following: Zero or more ebuilds. [...]" https://projects.gentoo.org/pms/6/pms.html#x1-340004.3 IIRC, the Perl team has a legitimate usage case for that.