When combine -D and -E together in euse, the result will only be -D or -E for all flags totally. Reproducible: Always Steps to Reproduce: 1.sudo euse -D Xaw3d gtk -E motif -p app-editors/emacs 2.sudo euse -E motif -D Xaw3d gtk -p app-editors/emacs Actual Results: For step1: Adding "app-editors/emacs[Xaw3d]" use flag in "/etc/portage/package.use/emacs" WARNING: USE flag "gtk" is already enabled for app-editors/emacs Adding "app-editors/emacs[gtk]" use flag in "/etc/portage/package.use/emacs" Adding "app-editors/emacs[motif]" use flag in "/etc/portage/package.use/emacs" All there flags are enabled. For setp2: WARNING: USE flag "motif" is already disabled for app-editors/emacs Adding "app-editors/emacs[-motif]" use flag in "/etc/portage/package.use/emacs" WARNING: USE flag "Xaw3d" is already disabled for app-editors/emacs Adding "app-editors/emacs[-Xaw3d]" use flag in "/etc/portage/package.use/emacs" Adding "app-editors/emacs[-gtk]" use flag in "/etc/portage/package.use/emacs" All three flags are disabled Expected Results: Something like this: cat /etc/portage/package.use/emacs app-editors/emacs -Xaw3d -gtk motif