I got an error when tried to emerge world. Error says what new icu and texlive-core can't be installed together. Is it correct? (dev-libs/icu-56.1:0/56::gentoo, ebuild scheduled for merge) pulled in by (no parents that aren't satisfied by other packages in this slot) (dev-libs/icu-55.1:0/55::gentoo, installed) pulled in by >=dev-libs/icu-50:0/55= required by (app-text/texlive-core-2015:0/0::gentoo, installed)
Could you please include the entire emerge output, and emerge --info?
Created attachment 424262 [details] emerge world -uDN -j3 --keep-going --info emerge world -uDN -j3 --keep-going --info > /tmp/emerge.world.log
Could you please try again with portage-2.2.27? It has a fix for some subslot regression.
I was not help. I had to unmerge list of depandant packages to emerge world emerge -C app-text/texlive-core media-libs/libvisio net-libs/webkit-gtk media-libs/libvisio app-text/libebook dev-tex/bibtexu dev-qt/qtcore dev-qt/qtwebkit net-libs/webkit-gtk media-libs/libcdr media-libs/raptor app-text/libmspub x11-drivers/xf86-video-amdgpu x11-drivers/xf86-video-ati After farther use flags changing problem was gone completely and now I can't reproduce it. Somehow portage remember libs verssions packets built with and ask for ther while world update. And of course new versions of libs can not be installed simultaneously with old ones. May be there are some fundamental bugs in portage...