busybox: fix build on musl.

srcpkgs/busybox/template

@@ -30,6 +30,12 @@ pre_build() {
 			-f ${wrksrc}/src/Makefile defconfig
 		cp -f ${FILESDIR}/${t}.dotconfig ${t}/.config
 			
+		case "$XBPS_TARGET_MACHINE" in
+		*-musl) sed -i -e /CONFIG_FEATURE_VI_REGEX_SEARCH/s/y/n/ \
+				-e /CONFIG_FEATURE_MOUNT_NFS/s/y/n/ \
+				${t}/.config;;
+		esac
+
 		if [ "$CROSS_BUILD" ]; then
 			sed -e \
 				"s,\(CONFIG_CROSS_COMPILER_PREFIX\).*,\1=\"${XBPS_CROSS_TRIPLET}-\",g" \