Unfixable breakage on wasm32?

[jvdwrf]

Hi, after updating to 1.13, my build for wasm32-unknown-unknown with js broke.

I already had the js feature enabled, however still I got the error that getrandom should have the wasm_js feature enabled.

I already have rustflags for wasm set to rustflags = ['--cfg', 'getrandom_backend="wasm_js"', '-Awarnings']. This is working fine for rand 0.9 which I am using myself. It is only uuid that causes the compilation error for getrandom 0.3.

I have tried a combination of using the uuid/js, uuid/getrandom and uuid/rand features, but the breakage stays. Downgrading to 1.12 fixes the issue for me. I am using uuid with features v4 and serde.

Any help would be much appreciated.

[hrzlgnm]

I'm also facing the issue that the newer version 1.13.1 fails to build, when renovate tries to update the lockfile

[KodrAus]

@jvdwrf What's the build error you're seeing?

[digimatic]

I started to get build errors with wasm32 after upgrading to latest toolchain 1.84.
Errors i get:

error[E0433]: failed to resolve: could not find `RngImp` in `imp`
   --> /Users/peterw/.cargo/registry/src/index.crates.io-6f17d22bba15001f/uuid-1.13.1/src/rng.rs:10:10
    |
10  |     imp::RngImp::u128()
    |          ^^^^^^ could not find `RngImp` in `imp`
    |
note: found an item that was configured out
   --> /Users/peterw/.cargo/registry/src/index.crates.io-6f17d22bba15001f/uuid-1.13.1/src/rng.rs:107:23
    |
107 |     pub(super) struct RngImp;
    |                       ^^^^^^
note: the item is gated behind the `rng-rand` feature
   --> /Users/peterw/.cargo/registry/src/index.crates.io-6f17d22bba15001f/uuid-1.13.1/src/rng.rs:106:11
    |
106 |     #[cfg(feature = "rng-rand")]
    |           ^^^^^^^^^^^^^^^^^^^^
note: found an item that was configured out
   --> /Users/peterw/.cargo/registry/src/index.crates.io-6f17d22bba15001f/uuid-1.13.1/src/rng.rs:126:23
    |
126 |     pub(super) struct RngImp;
    |                       ^^^^^^
note: the item is gated here
   --> /Users/peterw/.cargo/registry/src/index.crates.io-6f17d22bba15001f/uuid-1.13.1/src/rng.rs:125:5
    |
125 |     #[cfg(all(feature = "rng-getrandom", not(feature = "rng-rand")))]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: found an item that was configured out
   --> /Users/peterw/.cargo/registry/src/index.crates.io-6f17d22bba15001f/uuid-1.13.1/src/rng.rs:170:23
    |
170 |     pub(super) struct RngImp;
    |                       ^^^^^^
note: the item is gated here
   --> /Users/peterw/.cargo/registry/src/index.crates.io-6f17d22bba15001f/uuid-1.13.1/src/rng.rs:165:5
    |
165 | /     #[cfg(all(
166 | |         feature = "js",
167 | |         not(feature = "rng-rand"),
168 | |         not(feature = "rng-getrandom")
169 | |     ))]
    | |_______^

[KodrAus]

Ah, I think we should improve the error message you get there by adding a compile_error! block. The issue there looks like you're using uuid on wasm32-unknown-unknown without the js feature, relying on getrandom to provide a backend. You can either:

1. Add the js feature to uuid.
2. Add the rng-getrandom feature to uuid and use getrandom 0.3 to configure your backend.

[KodrAus]

I've added a more useful compile_error! message here when neither the js or rng-getrandom/rng-rand features are enabled and the target is wasm32-unknown-unknown. I'll go ahead and close this one now, but if there's any more detail to add please feel free to re-open or create new issues.