[Interest] appropriate versions of emscripten for 6.9

[Piotr Wierciński]

Hi!
The correct version of Emscripten for Qt 6.9 is 3.1.70, it has been updated recently in `QtPublicToolchainWasmHelpers`.
As for support of JSPI, `-sASYNCIFY=2` should work in Emscricpten 3.1.56. However, in 3.1.59 it got deprecated in favor of `-sJSPI` flag.
It is documented here: https://github.com/emscripten-core/emscripten/blob/main/ChangeLog.md#3159---043024.
Please note that using JSPI requires enabling it via experimental flag in Chrome.

There is still some work required for Qt to work smoothly with JSPI, but we are on our way to get there. 

Regards,
Piotr Wierciński


> -----Original Message-----
> From: Interest <interest-bounces at qt-project.org> On Behalf Of Glen Mabey
> Sent: Thursday, January 23, 2025 6:41 PM
> To: interest at qt-project.org
> Subject: [Interest] appropriate versions of emscripten for 6.9
>  
> It looks like (in QtPublicToolchainWasmHelpers.cmake) that the official version of emsdk to use with 6.9 will be 3.1.56 (same as 6.8).
> I'm trying (unsuccessfully so far) to get a QFileDialog to pop open from my QML app.
> I have been working to pursue the appropriate JSPI compile options, yet it seems that it (-sASYNCIFY=2) isn't supported in 3.1.56.
> So, I realize that JSPI isn't necessarily going to be supported in 6.9, but it's apparent (from the references to JSPI in the docs) that y'all are working towards that destination eventually (but not there yet).
> Or, is it just that QtPublicToolchainWasmHelpers.cmake needs to be updated?
> If not, then is there an emscripten version that you *have* had good success with?
> 
> Best Regards,
> Glen