Created attachment 558326 [details] build.log The app-emulation/virtualbox-guest-additions-5.2.22 re-emerge failed with the several pages of error messages like these: int hgsmi_get_mode_hints(PHGSMIGUESTCOMMANDCONTEXT ctx, ^~~~~~~~~~~~~~~~~~~~~~~~~ /var/tmp/portage/app-emulation/virtualbox-guest-additions-5.2.22/work/vboxvideo/vboxvideo_guest.h:168:26: error: unknown type name ‘PHGSMIGUESTCOMMANDCONTEXT’ int hgsmi_get_mode_hints(PHGSMIGUESTCOMMANDCONTEXT ctx, ^~~~~~~~~~~~~~~~~~~~~~~~~ /var/tmp/portage/app-emulation/virtualbox-guest-additions-5.2.22/work/vboxvideo/vboxvideo_guest.h:168:26: error: unknown type name ‘PHGSMIGUESTCOMMANDCONTEXT’ .... .... Downgrading sys-apps/sed back to 4.5, fixed the problem.
Created attachment 558328 [details] environment
Created attachment 558330 [details] emerge --info '=app-emulation/virtualbox-guest-additions-5.2.22::gentoo'
Created attachment 558332 [details] emerge -pqv '=app-emulation/virtualbox-guest-additions-5.2.22::gentoo'
Can you please try with sys-apps/sed-4.7 and report back your results?
app-emulation/virtualbox-guest-additions 5.2.22 and 6.0.0 build ok with sys-apps/sed-4.7