Using watch, WASM file is sometimes served truncated

[hubertp]

Recently (~24.02) started getting a spurious error in IDE on startup (won't even boot the list of projects):

Uncaught (in promise) CompileError: WebAssembly.instantiateStreaming(): section (code 10, "Code") extends past end of the module (length 29962350, remaining bytes 27208289) @+185753

A recompilation of GUI does the trick but it is quite annoying as there is no apparent rule on when it happens.
Any ideas?

[kazcw]

Is the file truncated on disk, or are we downloading it incompletely--in a bad build, what's the size of dist/gui/assets/pkg-opt.wasm?

[hubertp]

> ls -la dist/wasm/pkg*wasm
-rw-rw-r-- 1 hubert hubert 60077987 Mar  2 11:05 dist/wasm/pkg-opt.wasm
-rw-rw-r-- 1 hubert hubert 60077987 Mar  2 11:05 dist/wasm/pkg.wasm

[hubertp]

Note that reloading the page doesn't help. I have to re-run run command.

[kazcw]

Ok, it's definitely a build problem, probably specific to watch

[wdanilo]

We've observed it couple weeks ago already. Our diagnostics back then was that indeed the generated WASM file was OK but it was not SERVED correctly. Reloading the page does not fix that, as it seems that the server caches the truncated file. I was able to observe that together with @mwu-tow when the file was being served while being re-computed. Thus, stopping the watch and running it again was fixing the issue. @hubertp could you please confirm that it is also fixed on your end if you just re-run the watch command without any changes to the code, please?

Anyway, this needs to be investigated and it is a mystery for us why it started happening.

[hubertp]

@wdanilo yeap, running it again was what I was doing as well.

[wdanilo]

@hubertp would you be so nice and create issue for it, please? I think ti could be labeled as good first issue as I believe that people without a lot of insights into our codebase could try resolving it.

[hubertp]

Sure, reported under #5860

[wdanilo]

Thank you!