Re: [RFC PATCH 00/16] rust: allow older versions of rustc and bindgen

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

On Fri, 18 Oct 2024 at 16:43, Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 10/18/24 15:31, Daniel P. Berrangé wrote:
> > On Tue, Oct 15, 2024 at 03:17:18PM +0200, Paolo Bonzini wrote:
> >>                                                   Another possibility
> >> could be to accept Rust 1.64.0 but require installing a newer bindgen
> >> (0.66.x for example) on those two distros with an older release.
> >
> > How difficult is it to get newer 'bindgen' installed on these
> > platforms ? The audience here is not so much distros trying to
> > package new QEMU, as that's ony relevant for new distro, but
> > rather it is end usrs/contributors building QEMU for themslves.
>
> Very simple - "cargo install bindgen-cli", as already seen in the
> fedora-rust-nightly container's Dockerfile (note: building QEMU does
> _not_ need cargo).  In fact we could in fact do it via libvirt-ci, and
> it's quite possible that MacOS or some BSDs will need it.

Why doesn't 'rustup update' do this automatically? My Ubuntu 22.04
system I'm using 'rustup' to provide the rust toolchain,
and 'rustup update' updates rustc, cargo, clippy, etc, so
why isn't it also providing and updating bindgen?
('bindgen' for me is ~/.cargo/bin/bindgen, so not the system one.)
My expectation here was that "rustup update" would keep
the whole toolchain up-to-date...

thanks
-- PMM