Fixes for Rust 1.81.0

[leighmcculloch]

What

Fixes for Rust 1.81:

1. Update semver-checks to 0.35.0.

2. Don't use the extern function for invoking a contract function when executing tests.

Why

1. Semver checks is failing to run on the new version of Rust and needs updating.

2. Rust 1.81.0 changed the behavior of panics on extern "C" functions, such that panics cannot be caught by std::panic::catch_unwind.

   Contracts expose their functions as an extern function that defaults to extern "C". The test environment catches panics inside contract functions and resurfaces them as errors by using catch_unwind.

   The solution used was to make it so that the test environment never calls through the extern function, and instead calls through a non-extern function that does the same work. This seems like the sanest way to take away any dependence / relationship between the test environment and the Rust C-ABI so that any future changes to the C-ABI don't affect the test environment.

   An alternative solution would be to mark the contract function as extern "C-unwind" so that it retained unwind functionality, but that would continue to bind the SDK test environment to behaviour changes in extern fns.

   In the solution in this change the Abi qualifier "C" has been added. When the Abi qualifier is not specified it defaults to "C", but for the sake of being explicit and removing any doubt from a reader it is now specified. The Rust reference confirms that "C" is the default:

   • https://doc.rust-lang.org/reference/items/functions.html#extern-function-qualifier.

   More details on this change to Rust 1.81.0 can be found at:

   • https://blog.rust-lang.org/2024/09/05/Rust-1.81.0.html#abort-on-uncaught-panics-in-extern-c-functions
   • Tracking Issue for "C-unwind ABI", RFC 2945 rust-lang/rust#74990

   Close Rust 1.81.0 causes SIGABRT in test environment #1332

[tupui]

Oh great, thanks for the fix! I started getting these in my CI and was not sure if I needed to do something. Looks like I just need to wait for a new release 🙌

[leighmcculloch]

Planning a new release shortly!

[leighmcculloch]

Shortly as in hours, not days.

[tupui]

Awesome, thanks 🚀