Missing diagnostic in sub-crate if target is wasm32-unknown-unknown

[bug-brain]

When I set the target to wasm32-unknown-unknown most if not all diagnostics do not show up in sub-crates.

rust-analyzer version: rust-analyzer version: 0.3.2593-standalone (6b2e677 2025-08-25)

rustc version: rustc 1.90.0 (1159e78c4 2025-09-14)

editor or extension: VSCode 1.105.1

relevant settings: "rust-analyzer.cargo.target": "wasm32-unknown-unknown"

repository link: https://github.com/bug-brain/rust-analyzer-wasm

code snippet to reproduce:

async fn foo() {
    bar(); // no message
    let n = 0;
    n.await; // no message
}

[ChayimFriedman2]

There's nothing referring to sub in the top-level Cargo.toml. It shouldn't work in any target.

[bug-brain]

Oh, you are right. I am new to Rust and used the wrong commands to set up the reproducer. There must be something else in my project that causes this problem. I will update the description as soon as I find out more.

[bug-brain]

I tracked it down to the getrandom crate or something related to it. In my project I had to set the backend of two different versions of it because the feature flag had been renamed. With 0.3.4 i get the expected diagnostic messages but with 0.3.3 not (see updated repo).

[ChayimFriedman2]

If you run

cargo check --target=wasm32-unknown-unknown

Which is similar to what r-a runs, you'll get

The wasm32-unknown-unknown targets are not supported by default; you may need to enable the "wasm_js" configuration flag. Note that enabling the `wasm_js` feature flag alone is insufficient. For more information see: https://docs.rs/getrandom/0.3.3/#webassembly-support
   --> ...\getrandom-0.3.3\src\backends.rs:168:9
    |
168 | /         compile_error!(concat!(
169 | |             "The wasm32-unknown-unknown targets are not supported by default; \
170 | |             you may need to enable the \"wasm_js\" configuration flag. Note \
171 | |             that enabling the `wasm_js` feature flag alone is insufficient. \
172 | |             For more information see: \
173 | |             https://docs.rs/getrandom/", env!("CARGO_PKG_VERSION"), "/#webassembly-support"
174 | |         ));
    | |__________^

error[E0425]: cannot find function `fill_inner` in module `backends`
  --> ...\getrandom-0.3.3\src\lib.rs:99:19
   |
99 |         backends::fill_inner(dest)?;
   |                   ^^^^^^^^^^ not found in `backends`

error[E0425]: cannot find function `inner_u32` in module `backends`
   --> ...\getrandom-0.3.3\src\lib.rs:128:15
    |
128 |     backends::inner_u32()
    |               ^^^^^^^^^ not found in `backends`
    |
help: consider importing this function
    |
 33 + use crate::util::inner_u32;
    |
help: if you import `inner_u32`, refer to it directly
    |
128 -     backends::inner_u32()
128 +     inner_u32()
    |

error[E0425]: cannot find function `inner_u64` in module `backends`
   --> ...\getrandom-0.3.3\src\lib.rs:142:15
    |
142 |     backends::inner_u64()
    |               ^^^^^^^^^ not found in `backends`
    |
help: consider importing this function
    |
 33 + use crate::util::inner_u64;
    |
help: if you import `inner_u64`, refer to it directly
    |
142 -     backends::inner_u64()
142 +     inner_u64()
    |

For more information about this error, try `rustc --explain E0425`.
error: could not compile `getrandom` (lib) due to 4 previous errors

And if you'll navigate to this file, you'll see r-a is also showing this error.

As the message explains, enabling the feature is not enough.