Unable to --allow-privileged when using artifact reference syntax with FROM DOCKERFILE

[dustyhorizon]

What went wrong?
When the build chain requires RUN --privileged ..., FROM DOCKERFILE is not able to propagate the necessary flags to allow the artifacts to be properly copied.

A minimal Earthfile to reproduce this is as follows:

VERSION 0.7

source:
    RUN \
        --privileged \
        \
        set -ex \
        && touch a

    SAVE ARTIFACT a

build:
    FROM DOCKERFILE \
        -f +source/a \
        +source

It is also noted that there are no flags to specify --allow-privileged within a FROM DOCKERFILE command.

What should have happened?
By specifying earthly --allow-privileged +build I should be able to perform the build.

Other Helpful Information
Output from the minimal reproduction

❯ earthly -i -P +build
 Init 🚀
————————————————————————————————————————————————————————————————————————————————

           buildkitd | Found buildkit daemon as docker container (earthly-buildkitd)

 Build 🔧
————————————————————————————————————————————————————————————————————————————————

Error: Earthfile line 13:4 from dockerfile: earthfile2llb for +source: Earthfile line 4:4 Permission denied: unwilling to run privileged command; did you reference a remote Earthfile without the --allow-privileged flag?
in              x:develop+source
in              x:develop+build
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[dustyhorizon]

Still an issue on Earthly v0.8.3 with VERSION 0.8