Remove the --progress flag

[chanderlud]

Newer versions of Docker no longer support the --progress flag on the docker build command. This causes Cross to fail when using versions of Docker such as 23 and 24.

For example:

docker --version
Docker version 24.0.5, build 24.0.5-0ubuntu1~22.04.1
cross build --target aarch64-unknown-linux-gnu
info: downloading component 'rust-std' for 'aarch64-unknown-linux-gnu'
info: installing component 'rust-std' for 'aarch64-unknown-linux-gnu'
unknown flag: --progress
See 'docker --help'.

I have removed the progress code from cross in this pull request, this error no longer occurs.

[Emilgardis]

This pr solves a problem which doesn't exist, the situation here is unfortunate though.

We don't call docker build, we call docker buildx build , which absolutely does support --progress. The issue here is how docker handles error reporting. See https://github.com/cross-rs/cross/issues/1055

You should be getting an error message in the cross output suggesting how to fix this, which is to check that buildx/buildkit is available or to set CROSS_CONTAINER_ENGINE_NO_BUILDKIT=1

[chanderlud]

Yup, installing buildx got rid of the progress error. Do you think it would be reasonable for Cross to check if buildx is installed before trying to use it? That way a more helpful error message could be delivered to the user.

[Emilgardis]

If you can find a good way to detect buildx, I'd be happy to include a check like that!

[chanderlud]

It looks like the docker buildx version command is a good candidate for testing installation. I wrote this function to test for buildx being installed, but I am not sure what the best place to call it from would be.

fn is_buildx() -> bool {
    let mut cmd = Command::new("docker");
    cmd.args(["buildx", "version"])
        .output()
        // if buildx is present, it will print the version and exit 0
        // if buildx is not present, it will print a warning and exit 1
        .map_or(false, |out| out.status.success())
}