Hi, I am experimenting with building my compose multiplatform app for Wasm. I got it working with th...

# webassembly

[Thomas]

Hi, I am experimenting with building my compose multiplatform app for Wasm. I got it working with the wasmJsBrowserRun command. No errors, runs great. However, when I try to run a release version using wasmJsBrowserProductionRun or wasmJsBrowserDistribution I get the following error in the browser console, and just a white page:

Uncaught (in promise) CompileError: WebAssembly.instantiateStreaming(): Compiling function #33436 failed: type error in fallthru[0] (expected (ref null 23717), got (ref null 700)) @[phone]

I am using Kotlin 2.0.0. Is there anyway to debug this?

[Thomas]

Screenshot 2024-05-30 at 17.25.20.png

[Robert Jaros]

Can you share the code?

[Thomas]

Unfortunately not

[Thomas]

It’s a huge project and building a production build takes a few minutes, so it is hard to just comment out some code and try again.

[Robert Jaros]

I would say, this kind of errors happen to me when doing some unsafe casting.

[Robert Jaros]

But I can't help more. Perhaps someone else will be able to decode the error code.

[Svyatoslav Kuzmich [JB]]

This looks like an optimizer bug. Could you share dev .wasm binary that works?

[Thomas]

I can share it privately, will send it to you tomorrow.

[Svyatoslav Kuzmich [JB]]

Thanks! I’m interested in .wasm files from build/compileSync/wasmJs/main/productionExecutable/{kotlin,optimized}/*.wasm

Alternatively, if you would be willing to a bit of digging into compiled wasm code, I could provide some tips to localize the part of the code that is causing this problem, without sharing the binaries.