Stream: git-wasmtime

Topic: wasmtime / issue #11985 [wit-bindgen] Regression: previou...

Wasmtime GitHub notifications bot (Nov 05 2025 at 16:44):

anlavandier opened issue #11985:

Test Case

wasmtime = { version = "38", default-features = false, features = ["runtime", "component-model", "async"] }

use wasmtime::component::bindgen;

bindgen!({
    world: "bar",
    inline: "
    package example:example;

    interface api {
        foo: func();
    }

    world bar {
        import api;
    }
    ",
    imports: {
        "example:example/api/foo": async,
    }
});


fn main () {

}

This code compiles with the latest released version of wasmtime (38.0.3) but doesn't when using main, (29f2a1ca66c849a2d2e533a2df87c221daa8e2de at time of testing). The error is:

error: unused `imports` rules found: ["\"example:example/api/foo\": FunctionFlags(ASYNC)"]
  --> src/main.rs:3:1
   |
 3 | / bindgen!({
 4 | |     world: "bar",
 5 | |     inline: "
 6 | |     package example:example;
...  |
19 | | });
   | |__^
   |
   = note: this error originates in the macro `bindgen` (in Nightly builds, run with -Z macro-backtrace for more info)

Wasmtime GitHub notifications bot (Nov 05 2025 at 16:44):

anlavandier added the bug label to Issue #11985.

Wasmtime GitHub notifications bot (Nov 05 2025 at 16:44):

anlavandier edited issue #11985:

Test Case

wasmtime = { version = "38", default-features = false, features = ["runtime", "component-model", "async"] }

use wasmtime::component::bindgen;

bindgen!({
    world: "bar",
    inline: "
    package example:example;

    interface api {
        foo: func();
    }

    world bar {
        import api;
    }
    ",
    imports: {
        "example:example/api/foo": async,
    }
});


fn main () {

}

This code compiles with the latest released version of wasmtime (38.0.3) but doesn't when using main, (29f2a1ca66c849a2d2e533a2df87c221daa8e2de at time of testing). The error is:

error: unused `imports` rules found: ["\"example:example/api/foo\": FunctionFlags(ASYNC)"]
  --> src/main.rs:3:1
   |
 3 | / bindgen!({
 4 | |     world: "bar",
 5 | |     inline: "
 6 | |     package example:example;
...  |
19 | | });
   | |__^
   |
   = note: this error originates in the macro `bindgen` (in Nightly builds, run with -Z macro-backtrace for more info)

Wasmtime GitHub notifications bot (Nov 05 2025 at 18:33):

alexcrichton closed issue #11985:

Test Case

wasmtime = { version = "38", default-features = false, features = ["runtime", "component-model", "async"] }

use wasmtime::component::bindgen;

bindgen!({
    world: "bar",
    inline: "
    package example:example;

    interface api {
        foo: func();
    }

    world bar {
        import api;
    }
    ",
    imports: {
        "example:example/api/foo": async,
    }
});


fn main () {

}

This code compiles with the latest released version of wasmtime (38.0.3) but doesn't when using main, (29f2a1ca66c849a2d2e533a2df87c221daa8e2de at time of testing). The error is:

error: unused `imports` rules found: ["\"example:example/api/foo\": FunctionFlags(ASYNC)"]
  --> src/main.rs:3:1
   |
 3 | / bindgen!({
 4 | |     world: "bar",
 5 | |     inline: "
 6 | |     package example:example;
...  |
19 | | });
   | |__^
   |
   = note: this error originates in the macro `bindgen` (in Nightly builds, run with -Z macro-backtrace for more info)

Wasmtime GitHub notifications bot (Nov 05 2025 at 18:33):

alexcrichton commented on issue #11985:

Thanks for the report! I believe you're seeing the impact of https://github.com/bytecodealliance/wasmtime/pull/11947, which is an intentional change, so I'm going to close this. We'll be sure to call this out in the release notes for 39.0.0, however.

Last updated: Dec 06 2025 at 06:05 UTC