I have gentoo-sources pinned to 2.4.19-r5, this is however what happens: nosferatu gentoo-sources-2.4.19-r5 # emerge -up world These are the packages that I would merge, in order. Calculating world dependencies ...done! [ebuild N ] sys-apps/reiserfsprogs-3.1c to / [ebuild U ] media-sound/esound-0.2.28-r1 to / [ebuild U ] app-text/chktex-1.5-r2 to / [ebuild U ] dev-util/ltrace-0.3.26-r1 to / [ebuild U ] sys-kernel/gentoo-sources-2.4.19-r7 to / [ebuild U ] sys-apps/lsof-4.64 to / [ebuild U ] media-gfx/imagemagick-5.4.6 to / nosferatu gentoo-sources-2.4.19-r5 # cd .. nosferatu sys-kernel # mv gentoo-sources-2.4.19-r5/ gentoo-sources-2.4.19-r7 nosferatu sys-kernel # cd gentoo-sources-2.4.19-r7/ nosferatu gentoo-sources-2.4.19-r7 # mv gentoo-sources-2.4.19-r5.ebuild gentoo-sources-2.4.19-r7.ebuild nosferatu gentoo-sources-2.4.19-r7 # emerge -up world These are the packages that I would merge, in order. Calculating world dependencies ...done! [ebuild U ] sys-kernel/gentoo-sources-2.4.19-r5 to / [ebuild N ] sys-apps/reiserfsprogs-3.1c to / [ebuild U ] media-sound/esound-0.2.28-r1 to / [ebuild U ] app-text/chktex-1.5-r2 to / [ebuild U ] dev-util/ltrace-0.3.26-r1 to / [ebuild U ] sys-apps/lsof-4.64 to / [ebuild U ] media-gfx/imagemagick-5.4.6 to / nosferatu gentoo-sources-2.4.19-r7 # So it tries to install -r7 with -r5 installed, and then when I "have" -r7 installed, it tries to install -r5 again.
OK, Portage 2.0.30 is working a lot better in this regard, but it won't be perfect until emerge -u is SLOT-aware.