rust: add v1.72.0 for zenoh-c/0.10.1-rc

[oteffahi]

This PR adds Rust 1.72.0.

As mentionned in the Zenoh-C CCI PR, it would be ideal to have Rust 1.72.0 to ensure compatibility with Zenoh-C's 0.10.1-rc release artefacts, mainly regarding plugins.

[valgur]

@oteffahi
I already added 1.72, but added 1.72.1 instead of 1.72.0. Is that ok?

As mentionned in the Zenoh-C CCI PR, it would be ideal to have Rust 1.72.0 to ensure compatibility with Zenoh-C's 0.10.1-rc release artefacts, mainly regarding plugins.

Is this still relevant if we are building zenoh-c from scratch instead of using prebuilt binaries? Even then, Rust stdlib and other libraries are linked statically into the library, so I think the Rust version still should not really matter?

[oteffahi]

Hello @valgur,
Rust 1.72.0 is required in order for the resulting build to be compatible with prebuilt plugins and backends that are part of the 0.10.1-rc release. Zenoh users tend to want to use those without going through the bother of compiling them from source, so we want them to be supported if possible. This requires that both zenoh and the plugins must be built with the same Rust version, which in the case of 0.10.1-rc happens to be 1.72.0.
I hope this answers your question regarding this requirement.

[valgur]

Makes sense, thanks! I'll downgrade the version in the Rust recipe to 1.72.0.

[valgur]

Actually, on second thought, I would assume that 1.72.1 is still compatible with binaries built with the .0 version. Correct me if I'm wrong.

[oteffahi]

Actually, on second thought, I would assume that 1.72.1 is still compatible with binaries built with the .0 version. Correct me if I'm wrong.

@valgur sorry for the late reply. We haven't tested this, but ideally to avoid any possible issues it's better to use the exact same version. Note that we maintain a rust-toolchain.toml file which contains the exact version to be used when compiling the project. This version is downloaded and installed automatically by Cargo if building without providing a channel (i.e using cargo build instead of cargo +stable build or cargo +1.72.1 build for example)

I understand that you may want to support the latest patch of each minor version of Rust, but projects can require a specific version through their rust-toolchain.toml file, which might not be on the latest patch. In our case this is done in order to ensure compatibility with release artefacts (plugins).