Why is MSRV 1.79?

[nfejzic]

Hello! Nice work with the crate, really like it!

I have a question regarding the minimum supported rust version, which is at the moment of this writing set to 1.79. I tried building the crate on my machine using version 1.75 and it builds without any problems, tests run as well.

What is the reasoning behind setting the minimum supported Rust version to 1.79?

[nfejzic]

I just noticed that tests do not pass with Rust 1.75, std::num::NonZero is missing. So I assume that's the reason?

[tqwewe]

Ah yeah when I saw your issue initially I was trying to remember whats the reason, but as you've pointed out, its because of the NonZero types. I believe if you compile with the remote feature flag, you'll encounter errors since its used within the actor swarm registration error

[nfejzic]

Ok, so using it without the remote feature should work then with older rust versions as well? Would it be too much of a burden to document (and guarantee, maintain, etc.) the minimum supported version when not using remote? I would totally understand if it's too much work though 😄.

[tqwewe]

Absolutely, its a great suggestion! I added the MSRV before remote was behind a feature flag, but now that it is I can definitely improve documentation around this.

Does Rust let you use kameo on older versions even though the Cargo.toml file has rust-version = "1.79"? Would I need to remove that config from the Cargo toml?

[nfejzic]

Awesome, thank you!

No, it won't build with older versions if rust-version = "1.79" is present. Now that you mention it, it might be worth suggesting to cargo team such feature. Similar how we can have optional dependencies linked to features 🤔.

[nfejzic]

@tqwewe I opened an issue for Cargo: rust-lang/cargo#14770. While waiting for the response, I assume even if this feature is enabled, it won't be available in older cargo versions, making it irrelevant for this issue.

Have you thought about any alternatives? Maybe use rust_version crate to check if rust version is at least 1.79, otherwise emit a compile_error? 🤔

EDIT: Another possible workaround could be to factor out the remote module to a separate crate as an extension for kameo. This would make it possible to have separate MSRV versions for kameo and kameo_remote

[tqwewe]

Hi sorry for the late reply. Thanks for taking the time to open the issue on cargo GH
I haven't heard of rust_version crate but this could definitely work.

I also am open to the idea of kameo_remote. Is there a particular reason upgrading Rust version isn't possible in your case?

[nfejzic]

I also am open to the idea of kameo_remote. Is there a particular reason upgrading Rust version isn't possible in your case?

That would be nice! As for the reason, we're currently developing software for embedded devices and we use Yocto for this purpose. Unfortunately, upgrading Rust in such environments is not always easy and straightforward. We are working on it, so maybe we will succeed and this won't be necessary, but for now we can't use the crate because it doesn't build with lower rust versions.

[tqwewe]

Sorry for the delay, this should be resolved in 0.13 of kameo

[nfejzic]

Sorry for the delay, this should be resolved in 0.13 of kameo

No problem, thank you very much!