Perhaps it’s just too late for me to get it… but I’ve pushed what I have (working) here: https://github.com/pantsbuild/pants/pull/13386/commits/6025b3e843b469accc1e22f53fb7493eab912bb9#diff-230e01d4da02868508b[…]cdb86ee8680b8d26R133-R137 It’s the next step, to wire this codegen target up with

docker_image

that proved problematic (but I see a way forward, albeit, perhaps not the most elegant yet..)