Include github actions runs-on field in key.

[rukai]

I just hit a confusing compilation issue when downgrading from runs-on: ubuntu-20.04 to runs-on: ubuntu-18.04 caused because the cache didnt clear.
I'm not sure if you have access to this field, maybe something similar could be done by looking at something like lsb_release -a

[jessestricker]

I am not sure if this is related, but I get this error on my workflow:

error: failed to select a version for the requirement `clap = "=4.0.15"`
candidate versions found which didn't match: 3.2.22, 3.2.21, 3.2.20, ...
location searched: crates.io index

I run the job with the following matrix:

rust-version: ["1.56", stable]
runner: [ubuntu-latest, macos-latest]

Locally, building works with both versions with a clean cache.

[rukai]

I think that is unrelated to this issue, your issue is to do with dependency resolution while this issue is caused by different versions of ubuntu having different versions of external c/c++ dependencies.

I suspect the difference in behavior you are experiencing is due to your local Cargo.lock file.
Try deleting that and seeing if you can reproduce the problem locally that way.
I'm just guessing from the error message, but if you have set clap = "=4.0.15" that can cause all sorts of problems with dependency resolution and you would be better off specifying it as just clap = "4.0.15".

[jessestricker]

Thanks for your suggestions.

I suspect the difference in behavior you are experiencing is due to your local Cargo.lock file.
Try deleting that and seeing if you can reproduce the problem locally that way.

I have the same Cargo.lock file committed to the repo for reproducibility, so it should work in both CI and local. Also I run cargo with the --locked flag in CI.

you would be better off specifying it as just clap = "4.0.15"

I do actually specify the dependency as clap = { version = "4.0.15", features = ["derive"] }. I suspect the constrain on =4.0.15 is because that's the version in the Cargo.lock file as well.