Re: [PATCH] configure, meson: synchronize defaults for configure and Meson Rust options

[Peter Maydell <peter.maydell@linaro.org>]

On Mon, 14 Oct 2024 at 12:01, Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> If the defaults for --enable-rust ($rust in configure) and Meson's rust
> option are out of sync, incremental builds will pick Meson's default.
>
> This happens because, on an incremental build, configure does not run
> Meson, Make does instead.  Meson then gets the command line options
> from either coredata.dat (which has everything cached in Python's pickle
> format) or cmd_line.txt (slow path when Meson version is upgraded), but
> neither knows about the rust option, and the meson_options.txt default
> is used.
>
> This will cause have_rust to be true if rustc is available; and the build
> to fail because configure did not put a RUST_TARGET_TRIPLE in config-host.mak.
>
> When in the Rust pull request I changed the $rust default from auto
> to disabled, I should have made the same change to meson_options.txt;
> do it now.
>
> Cc: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> Reported-by: Peter Maydell <peter.maydell@linaro.org>
> Reported-by: Daniel P. Berrangé <berrange@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

This fixes the issue I was seeing with my local
incremental rebuild.

Tested-by: Peter Maydell <peter.maydell@linaro.org>

-- PMM