OS Version of Rust

[dcampbell24]

Why don't you at least use the version of Rust for tests that the operating system comes with? For example Ubuntu 24.04 ships with 1.75. I don't think you will find 1.36 on a Ubuntu 24.04 system.

[vorner]

Hello

Could you provide some context of what you're actually talking about? The CI? If it's the CI, the answer mostly is… I didn't have time to keep it up to date and it is kind of rotten. Needs love and time and I don't really have enough of the latter to give it any right now :-(

[dcampbell24]

Yeah, I'm talking about CI. Oh, well I can update Ubuntu. I don't know about all the other tests. Just it seemed strange that there are so many tests failing. If you're too busy, it is understandable.

[dcampbell24]

According to cargo msrv find your minimum Rust version is currently at 1.78.0.

[dcampbell24]

When I delete the Cargo.lock file and set rust-version = 1.36, version 1.63.0 is still required because of libc v0.2.175.

[dcampbell24]

You have to set rust-version to avoid cargo using a format that limits the possible rust versions.

[vorner]

As far as msrv goes, this is a bit more complex.

Dev dependencies need something and all the signal-hook-$something_asynchronous probably need new enough things.

However, the signal-hook-registry and signal-hook have only one dependency, specified as libc = "^0.2". Provided the Cargo.lock is not used from libraries, but only the „top-level“ crate provides the effective one, if you run very old rustc / cargo and take care to set your own version of libc to something old enough, it should still work all the way back to something like 1.36. But you need to do some manual work and poke the dependency resolution a bit, certainly not something that would work auto-resolution any more. Not sure if anyone goes through that, though.

The CI in that regard was originally set up to check for this. Unfortunately, it seems it wasn't written in a way that'd keep working when things keep updating in the world :-|.

[dcampbell24]

You can't go much lower than rust-version 1.63 without changing a bunch of other dependencies besides libc. I tried, but gave up. 🤷 I would probably update the tests to use rust-version 1.63, set rust-version 1.63, delete and re-create the Cargo.lock file or .gitignore it, because what is the point in having a test that always fails. Or you can change a lot of other dependencies and set the rust-version lower. Is anyone really stuck on a version of Rust lower than 1.63?

[dcampbell24]

This is including the dev and build dependencies which affect the msrv.

[dcampbell24]

(and your real MSRV right now is 1.78.0)

[vorner]

The test certainly shouldn't always fail, that's the part of the CI being rotten.

However, I've just tried and the current crate still can be compiled with 1.36. This is my Cargo.toml of the test:

[package]
name = "old-stuff"
version = "0.1.0"
authors = ["Michal 'vorner' Vaner <vorner@vorner.cz>"]
edition = "2018"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
signal-hook = "0.3"
libc = "=0.2.50"

This doesn't apply to all the async crates on top of these (which also sit in the same git repo), but the test shouldn't be testing these.

And no, dev dependencies are not relevant to the end user of the crate (build dependencies are, if they are used - and cc is optional here).

Now, I'm open to discussing if it still makes sense to support such an old Rust (and given a meaningful feature that we could add that would mean breaking it might be a good argument), or if it makes sense to disable the broken tests if fixing them is too much work, but I'd say the argument that the MSRV is 1.78.0 is not true.