Mounting secret with `required` works dockerfile:1.2 breaks in dockerfile:1.3

[sindreij]

This command breaks in 1.3, but works using # syntax = docker/dockerfile:1.2:

RUN --mount=type=secret,id=poetry_secret,required,dst=/root/.config/pypoetry/auth.toml poetry install

The error:

--------------------
  21 | >>> RUN --mount=type=secret,id=poetry_secret,required,dst=/root/.config/pypoetry/auth.toml poetry install
  22 |
--------------------
error: failed to solve: dockerfile parse error on line 21: unexpected key 'required' for mount type 'bind'

Command used to build:

buildctl build --frontend=dockerfile.v0 --opt filename=Dockerfile --local context=. --local dockerfile=. --secret id=poetry_secret,src=poetry.txt

[crazy-max]

@sindreij Might be linked to #2089 (cc @omermizr).

In the meantime you can use required=true instead of required.