build-sys: update build sys to darvaza.org/x's latest

Signed-off-by: Alejandro Mery <amery@jpi.io>

pkg/tools/gen_index.sh

@@ -5,8 +5,7 @@ set -eu
 : ${GO:=go}
 
 MODULES=$(find * -name go.mod -exec dirname '{}' \;)
-GROUPS="pkg cmd"
-BASE="$PWD"
+GROUPS=""
 
 mod() {
 	local d="${1:-.}"