Re: [gentoo-dev] dev-python/cryptography to use rust, effectively killing alpha, hppa, ia64, m68k, s390

[Michał Górny]

On Mon, 2021-02-08 at 18:56 +0100, Alessandro Barbieri wrote:
> Il Lun 8 Feb 2021, 12:19 Michał Górny <mgorny@g.o> ha scritto:
>
> > Hi,
> >
> > FYI the developers of dev-python/cryptography decided that Rust is going
> > to be mandatory for 1.5+ versions.  It's unlikely that they're going to
> > provide LTS support or security fixes for the old versions.
> >
> > Since cryptography is a very important package in the Python ecosystem,
> > and it is an indirect dependency of Portage, this means that we will
> > probably have to entirely drop support for architectures that are not
> > supported by Rust.
> >
> > According to upstream platform support information [1], this probably
> > means (eventually) entirely removing the following architectures:
> > - alpha (stable)
> > - hppa (stable)
> > - ia64 (stable)
> > - m68k (exp)
> > - s390 (except for s390x, exp)
> >
> > Furthermore, the Gentoo Rust packages are missing support
> > for the following platforms, apparently supported upstream:
> > - mips (exp)
> > - ppc (32) (stable)
> > - sparc (stable)
> > - s390x (exp)
> > - riscv (stable)
> >
> > Apparently it's non-trivial to bootstrap Rust on these platforms,
> > so it's unclear when Gentoo is going to start providing Rust on them.
> >
> > I've raised a protest on the cryptography bug tracker [2] but apparently
> > upstream considers Rust's 'memory safety' more important than ability to
> > actually use the package.
> >
> > Honestly, I don't think it likely that Rust will gain support for these
> > platforms.  This involves a lot of work, starting with writing a new
> > LLVM backend and getting it accepted (getting new code into LLVM is very
> > hard unless you're doing that on behalf one of the big companies).  You
> > can imagine how much effort that involves compared to rewriting the new
> > code from Cryptography into C.
> >
> > If we can't convince upstream, I'm afraid we'll either have to drop
> > these architectures entirely or fork Cryptography.
> >
> >
> > [1] https://doc.rust-lang.org/nightly/rustc/platform-support.html
> > [2] https://github.com/pyca/cryptography/issues/5771
> >
> > --
> > Best regards,
> > Michał Górny
> >
>
> Should we shed tears for those legacy architectures or move forward? Does
> anyone really use them in production?

I'm pretty sure people do use them in production.  Whether we want to
really continue supporting them is a separate topic.  But the last thing
I'd like to do is drop support for arches because of a single upstream
maintainer being a Rust lover.

-- 
Best regards,
Michał Górny