Yesturday, I run 'emerge -uDN @world' then 'revdep-rebuild' and finally 'emerge -p --depclean'. On the last step, I see that portage wants to clean gentoo-sources-2.6-31-r6 without any kernel version to replace it. I run 'emerge -p gentoo-sources' and portage returns me '[ebuild NS ] sys-kernel/gentoo-sources-2.6.31-r10'. Why portage doesn't install the new slot with my first command as usual ? Is it a new behaviour of portage ? Reproducible: Didn't try
Chances are that 'emerge -uDN --with-bdeps y @world' would have picked it up.
It does not for the same reason it depcleaned gentoo-sources. You will have installed gentoo-sources using the --oneshot option, so it isn't recorded in the world file. Since nothing depends on gentoo-sources it's a leaf falling from the dependency tree and Portage doesn't care about it. This is a feature not a bug.
Yes, gentoo-sources was in my world and I emerged it _without_ --oneshot.