Uncaught (in promise) RuntimeError: unreachable

[maninkari]

Hi, I am trying to use image and imageproc functions but keep getting in both cases a runtime error mentioning unreacheable. Any clues why this could be? I am compiling my code into wasm using cargo/wasm-pack. Thank you!

example:

let w = 200;
let h = 200;

let img = ImageBuffer::from_fn(w, h, |x, y| {
    if (x + y) % 3 == 0 {
        image::Rgba([0, 0, 0, 255])
    } else {
        image::Rgba([255, 255, 255, 255])
    }
});

img.save("out.png").unwrap();

[HeroicKatora]

I tried fixing the link but it appears to not have been uploaded successfully. Could you have a look and ensure that the image causing the error is available?

[maninkari]

Hi, thanks for looking into this. I just updated my initial comment.

[HeroicKatora]

Weird, core::option::expect_none_failed is not what I would expect in a stacktrace that ends with unreachable. It seems like an assertion triggered (possibly this one) but the wasm compilation translates this to unreachable somehow. Did you compile with panic=abort?

[maninkari]

No, just wasm-pack build --target web

[gitcoinbot]

Issue Status: 1. Open 2. Started 3. Submitted 4. Done

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Issue Status: 1. Open 2. Started 3. Submitted 4. Done

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Work has been started.

These users each claimed they can complete the work by 1 month from now. Please review their action plans below:

1) zhyd1997 has started work.

try cargo 1.56.0 (4ed5d137b 2021-10-04) and ustup 1.24.3 (ce5817a94 2021-05-31)

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Issue Status: 1. Open 2. Started 3. Submitted 4. Done

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Work for 40.028 USD (40.0 USD @ $1.0/USD) has been submitted by:

1. @zhyd1997

@birdlavv please take a look at the submitted work:

• PR by @zhyd1997

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[birdlavv]

Apologies @zhyd1997, I was unable to get a working WASM package built with those specific versions of rustup and cargo and your PR.

I've made a reproduction repo here: https://github.com/birdlavv/image-rs-1471-reproduction

[zhyd1997]

@birdlavv So what're versions of rustup and cargo you used?

And node -v?

[zhyd1997]

Here is mine:

[birdlavv]

Sorry @zhyd1997 for the miscommunication, I was unable to get the build working- after I had installed the versions you specified.

Here are my versions:

[zhyd1997]

change your code like so, and reproduce as README described.

[zhyd1997]

@birdlavv You can copy the code here: https://crates.io/crates/console_error_panic_hook

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Issue Status: 1. Open 2. Started 3. Submitted 4. Done

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[birdlavv]

Aha! It the hook produces:

panicked at 'called `Result::unwrap()` on an `Err` value: IoError(Error { kind: Unsupported, message: "operation not supported on this platform" })', src/lib.rs:20:25

After removing the img.save("out.png").unwrap(); line it ran successfully!

I believe this is because WASM does not have access to the filesystem. Thanks @zhyd1997! Bounty paid & closed.