It's a bug. Shouldn't happen: emerge: there are no ebuilds built with USE flags to satisfy ">=x11-base/xorg-server-1.7[-minimal]". !!! One of the following packages is required to complete your request: - x11-base/xorg-server-1.7.3.901-r1 (Change USE: -minimal) (dependency required by "media-libs/mesa-7.7" [ebuild]) (dependency required by "@world" [argument]) as it was working flawlessly with USE=minimal. Reproducible: Always
You appear to have media-libs/mesa unmasked but not x11-base/xorg-server-1.7. In the only xorg-server-1.7 ebuild, USE=-minimal pulls in three packages critical to media-libs/mesa (notably DRI support): !minimal? ( >=x11-proto/xf86driproto-2.1.0 >=x11-proto/dri2proto-2.1 >=x11-libs/libdrm-2.3.0 ) So whatever you think USE=minimal should mean, it only draws in whatever mesa needs to support DRI.