SSE2 required for i686 targets in rust >= 1.86

[Jakub Bogusz]

On Fri, May 16, 2025 at 12:27:34PM +0200, Jan Palus wrote:
> Starting with rust 1.86 binaries built for i686 (including rustc itself)
> require SSE2 instructions (refer to release notes for rationale). The
> question is how we'd like to handle this:
> 
> 1. Change target to i586-unknown-linux-gnu for i686.
>    i586-unknown-linux-gnu is "Tier 2 platform without host tools" so
>    we'd need to build both i686-unknown-linux-gnu for tools which would
>    require SSE2 as well as i586-unknown-linux-gnu.
> 
> 2. Put "Requires: cpuinfo(sse2)" possibly through some %rust_req macro
>    in every package utilizing rust
> 
> 3. Change our baseline for i686 so SSE2 is mandatory and do nothing.
> 
> Any other ideas are welcome.

1 looks like big PITA, so I'd go with 2...


-- 
Jakub Bogusz    http://qboosh.pl/