Incorrectly removing async from extern "C" blocks

[pauldorehill]

Describe the bug

When running rustfmt async is removed from my functions:

To Reproduce
Add any extern block with async, run cargo fmt and the async will be removed:

#[wasm_bindgen(module = "clock")]
extern "C" {
    #[wasm_bindgen]
    async fn strike_thirteen();
}

becomes

#[wasm_bindgen(module = "clock")]
extern "C" {
    #[wasm_bindgen]
    fn strike_thirteen();
}

Expected behavior
My async stays

Meta

• rustfmt version: 1.4.15-stable
• From where did you install rustfmt: rustup
• How do you run rustfmt: cargo fmt (also VSCode + rust-analyzer)

[calebcartwright]

Thank you for the report @pauldorehill. This is a duplicate of #4288 that's already been addressed in source but just hasn't been released yet. Closing accordingly

[pauldorehill]

Ah apologies... I only searched open

[calebcartwright]

No worries! We've got quite a lot of unreleased changes on the master branch, and myriad associated issues that have been closed, so it can be trickier than usual to tell sometimes. Thanks again for reaching out!