`ctx.actions.write` doesn't propagate `with_inputs` dependencies if given an `OutputArtifact` rather than a `str` filename

[lf-]

We found a funny behaviour: if you use an Artifact in AnalysisActions.write() or AnalysisActions.write_json(), it won't propagate dependencies when with_inputs is True; you have to use the return value. This isn't true of e.g. ctx.actions.run, e.g., I think?

@JakobDegen says this is still a bug in main.

This gets annoying if one is using dynamic actions since the dynamic actions cannot pass anything out to the non-dynamic world except by putting something into an artifact, and you can't just .. replace the identity of the artifact like we have to do in this example:

Good:

    written = ctx.actions.write(
        "container_upload.sh",
        cmd_args(
            "#!/usr/bin/env bash",
            "set -euo pipefail",
            cmd_args(
                # ctx.attrs.build_container,
                "FIXME",
                cmd_args(build_plan, quote = "shell"),
                "\"$@\"",
                delimiter = " ",
            ),
        ),
        is_executable = True,
        with_inputs = True,
    )

Bad:

    runner = ctx.actions.declare_output("container_upload.sh")
    ctx.actions.write(
        runner.as_output(),
        cmd_args(
            "#!/usr/bin/env bash",
            "set -euo pipefail",
            cmd_args(
                # ctx.attrs.build_container,
                "FIXME",
                cmd_args(build_plan, quote = "shell"),
                "\"$@\"",
                delimiter = " ",
            ),
        ),
        is_executable = True,
        with_inputs = True,
    )

[cormacrelf]

https://buck2.build/docs/api/build/Artifact/#artifactwith_associated_artifacts

There's no mutating variant of this. You would need one, or at least for such a method to exist on the rust side. I bet you $5 that Artifact is an Arc under the hood and can't be mutated easily.