Enable grub configuration generator

Packages describing “grub” as local USE flag

Package “grub” Flag Description
dev-util/ostree Enable grub configuration generator
kde-plasma/plasma-meta Pull in Breeze theme for sys-boot/grub
x11-themes/gentoo-artwork Install extra sys-boot/grub themes
sys-kernel/installkernel-gentoo Re-generate grub.cfg on each kernel installation

All packages providing a “grub” USE flag (3)