libgnomeui 2.26.0 is not yet released. It is not present neither in svn nor on ftp so it cannot be downloaded. However it found its way into gnome-overlay. Reproducible: Always
Sorry, can't find it: ~/devel/overlays/gnome $ find -name "*.ebuild" |egrep "gnomeui" Nor in the deps of another package: ~/devel/overlays/gnome $ egrep "libgnomeui" * -r closing invalid for now.
Ups. My error. I tried to get it. I failed. I forgotten to remove it. I forgotten about it. I blamed gnome herd. Sorry