There is recent update that enables such functionality - https://github.com/moby/buildkit/releases/tag/dockerfile/1.7.0-labs To work with it - add comment in the beginning of the Dockerfile # syntax=docker.io/docker/dockerfile:1.7-labs

Available in docker/dockerfile-upstream:master-labs. Will be included in docker/dockerfile:1.7-labs.

Use the syntax parser directive to declare the Dockerfile syntax version to use for the build. If unspecified, BuildKit uses a bundled version of the Dockerfile frontend. Declaring a syntax version lets you automatically use the latest Dockerfile version without having to upgrade BuildKit or Docker Engine, or even use a custom Dockerfile implementation.

Provides empty Module#ruby2_keywords method, for the forward source-level compatibility against ruby2.7 and ruby3.

GraphQL services should not provide any additional entries to the error format since they could conflict with additional entries that may be added in future versions of this specification.