How to select version

[frosch01]

Hi,

when I check the code, it seems there are many different cargo version supported at the same time. Can you please update documentation on how a version can be selected. I was not able to find an answer looking at the Yocto documentation.

Thx

Ralph

[seimonw]

I use yocto's PREFERRED_VERSION variable, set in my local.conf:

PREFERRED_VERSION_rust-bin-cross-arm = "1.76.0"
PREFERRED_VERSION_cargo-bin-cross-arm = "1.76.0"

[robagar]

Is it possible to select the rust version on a per-recipe basis? Generally I want to use latest stable rust, but some things need a fixed version (specifically in our case, Zenoh needing to built with rust 1.75)

[seimonw]

I don't think there's an easy way to do this, to my knowledge you can't have two versions of a package at the same time.
Only thing I could think of is something like creating your own cargo-bin-175 class and pulling that into your zenoh recipe instead of the regular class.
Feels a bit messy, but might work!

[nastevens]

There's no guide for it at the moment, but it should be possible to use Yocto multiconfig to do this. There's a short guide here and more details in the Yocto documentation itself.

If you get this working it'd be awesome to see your notes on how!

[seimonw]

Yeah, that works @nastevens

I was able to create a build/conf/multiconfig/rust-175.conf:

PREFERRED_VERSION_rust-bin-cross-arm = "1.75.0"
PREFERRED_VERSION_cargo-bin-cross-arm = "1.75.0"

Add BBMULTICONFIG = "rust-175" to my local.conf

Then bitbake mc:rust-175:myrustdemo

In myrustdemo's log.do_compile I can see

NOTE: rustc --version rustc 1.75.0 (82e1608df 2023-12-21)
NOTE: cargo --version cargo 1.75.0 (1d8b05cdd 2023-11-20)

[nastevens]

That's great, thanks for testing that out @seimonw!