-[[ -x ${chr}/usr/bin/time ]] || pkgs+=( time )
-[[ ${#pkgs[@]} -eq 0 ]] || cros_sdk -- sudo emerge -1 ${pkgs[@]}
+[[ -x ${chr}/usr/bin/time ]] || pkgs+=( sys-process/time )
+[[ -x ${chr}/usr/bin/gdb ]] || pkgs+=( sys-devel/gdb )
+[[ -x ${chr}/usr/bin/diffstat ]] || pkgs+=( diffstat )
+[[ ${#pkgs[@]} -eq 0 ]] || cros_sdk -- sudo emerge -1q --jobs ${ncpus} ${pkgs[@]}
+cros_sdk -- sudo eupdatedb -q &