I just release v1.0.0 Beta 1 of my actions-rust-cross GitHub Action. The big headline feature in this release is integration with the Swatinem/rust-cache action. This will include the target you provide to actions-rust-cross as part of the cache key, which from my testing means that it only caches the compilation output relevant to the target platform.
The Swatinem/rust-cache action caches compiled dependencies, so how helpful this will be for your project depends on how much time it spends compiling dependencies versus the project itself.
From some informal testing with my ubi project, I saw that caching reduced build and test time for 21 different targets from 9.5 minutes to around 4.5 minutes. That project has about 255 crate dependencies when I run cargo test.
Note that according to the docs for Swatinem/rust-cache, this caching is most useful for projects with a Cargo.lock file in their repo. For libraries, this caching is less helpful, since cargo is always pulling new dependency versions as they’re released. However, I suspect that for runs in quick succession this caching might still work well. You can always disable caching entirely by setting use-rust-cache to false when invoking actions-rust-cross.
You can also configure the Swatinem/rust-cache action by passing a JSON string in the rust-cache-parameters parameter to actions-rust-cross. This is a bit awkward, but it was the best way I could figure out how to take parameters without copying all of the rust-cache parameters to actions-rust-cross.
In order to take advantage of this release, you just need to change your uses to houseabsolute/actions-rust-cross@v1. If you’re already calling Swatinem/rust-cache separately from actions-rust-cross, you should delete that from your workflow.
I’d love to get some feedback on this release before marking it stable. If you try it and it doesn’t work, please file a GitHub issue. If it does work for you, please email me and let me know!