chore: get rid of now-stabilized error_in_core feature

[TheButlah]

Attempting to build the SDK without stable compiler features is not possible right now due to the use of #![feature(error_in_core)]. However, this feature was stabilized in rust 1.81 in September 2024.

It would be good to remove the now-unneeded unstable flag.

[ivila]

Thanks for contributing.

Our main blocker is that we’re currently tied to Rust 1.80 (see the toolchain file) because of the patched standard library we rely on (see development-modes).

Removing this constraint would break our build pipeline.

[ivila]

@DemesneGH Should we update our patched version? We’re starting to run into more issues as it ages — the current patch is from 2024-05-14.

[DemesneGH]

@DemesneGH Should we update our patched version? We’re starting to run into more issues as it ages — the current patch is from 2024-05-14.

Sure, since I’ve been quite busy recently, I’ll make it my top priority on the todo list.

[TheButlah]

in the meantime then, ill update my PR with a path forward:

• Ill detect the rustc version being used in the build script
• If its too old, ill enable the nightly feature, otherwise I wont.
• It would continue to support the older MSRV

This would unblock using stable toolchains for no-std users, without requiring yall to upgrade the repo's rust-toolchain.toml

[ivila]

in the meantime then, ill update my PR with a path forward:

• Ill detect the rustc version being used in the build script
• If its too old, ill enable the nightly feature, otherwise I wont.
• It would continue to support the older MSRV

This would unblock using stable toolchains for no-std users, without requiring yall to upgrade the repo's rust-toolchain.toml

Please also add a brief comment explaining this logic, so we can remove it once we upgrade the toolchain version.

For example: https://github.com/apache/teaclave-trustzone-sdk/blob/main/optee-utee/macros/Cargo.toml#L33-L38

[ivila]

There’s also an example that uses the same logic you need — you may want to take a look at that as well.

https://github.com/chelsea0x3b/dfdx/blob/main/dfdx/build.rs#L8-L18
https://github.com/chelsea0x3b/dfdx/blob/main/dfdx/src/lib.rs#L253

[TheButlah]

Closing in favor of #260