Unsafe usage problem in 1.88 (code is compiling with Version ="2021" and failing with Version = "2024"

[ProfSecOps]

Code

unsafe(plugin_interface! {
   extern trait ExamplePlugin {
        /// Ask the plugin to do a thing
        fn do_a_thing();
        /// Say hello to a person
        fn say_hello(to: *const c_char) -> bool;
        /// Here's a function
        fn trigger_function(a_func: extern "C" fn(u32, u32));
    }
})

Current output

Compiling sxarc_host v0.7.0 (C:\DEV\sxarc\exec\sxarc_host)
error: expected item, found keyword `unsafe`
 --> exec\sxarc_host\src\lib.rs:4:1
  |
4 | unsafe(plugin_interface! {
  | ^^^^^^ expected item
  |
  = note: for a full list of items that can appear in modules, see <https://doc.rust-lang.org/reference/items.html>

error: could not compile `sxarc_host` (lib) due to 1 previous error

Desired output

edition = "2021" it is compiling

edition = "2024" is throwing the above error

Rationale and extra context

Original Code is from : https://github.com/lilopkins/dynamic-plugins-rs/tree/main

Was changing the project structure and actualizing all crate versions to the latest one.

Other cases

Rust Version

rustc 1.88.0 (6b00bc388 2025-06-23)
binary: rustc
commit-hash: 6b00bc3880198600130e1cf62b8f8a93494488cc
commit-date: 2025-06-23
host: x86_64-pc-windows-msvc
release: 1.88.0
LLVM version: 20.1.5

Anything else?

Was only changing the Project Structure to (see picture) and updating all cartes / Versions to the newest one.

[AngelicosPhosphoros]

You are writing incorrect syntax, what did you expect?

Correct way to use linked crate is

plugin_interface! {
   extern trait ExamplePlugin {
        /// Ask the plugin to do a thing
        fn do_a_thing();
        /// Say hello to a person
        fn say_hello(to: *const c_char) -> bool;
        /// Here's a function
        fn trigger_function(a_func: extern "C" fn(u32, u32));
    }
}

If this causes compilation errors due to having unsafe code, it is the code in dynamic-plugin must be fixed.

rustc have not broke backward compatibility here: the problem doesn't happen in code that compiled using 2021 version.

You probably should open an issue in the repo you have linked.