pthread send an error (qtloader.js)

[banana.joe]

Hey,

currently I'm porting my PyQT based project (Pythonic) to Qt WASM.

It general it works pretty well but I got stuck when I wanted to use multi-threading due to drag & drop support. I followed the instructions on the related wiki page:

• Cloned the Qt Git-repository (git://code.qt.io/qt/qt5.git)
• Checkout 5.15.1 branch
• Init repository
• Configured and build with emsdk 1.39.8

To provide the webdata I run the eventlet WSGI server: I also set the header:

When I open http://localhost:7000/ on Firefox 81.0.1, I only see the Qt logo but it gets stuck during loading. The console output in Firefox says:

pthread sent an error! qtloader.js:382:25

The mentioned line in qtloader.js is only the Module.prinerr method so I assume that not the root cause.

What could went wrong here?
How can I further debug this issue?
Should I have used Qt v5.15 instead of 5.15.1?

You can reproduce the behavoir with the following steps:

• git clone https://github.com/hANSIc99/Pythonic.git
• git checkout dev
• cd Pythonic/src/PythonicWeb/
• python3 main.py
• Open A browser an go to http://localhost:7000/

Thank you in advance!

[jsulm]

@banana-joe said in pthread send an error (qtloader.js):

multi-threading due to drag & drop support

Why do you need multi-threading for drag&drop?!

[banana.joe]

@jsulm I get an exception message when the exec() method (QDrag) is called (toolmaster.h: mousePressEvent). I thought it wad due to the missing multithreading support.

This is the error message when I compile it with the default 5.15.1 binaries (console output in Firefox):

Uncaught Please compile your program with async support in order to use asynchronous operations like emscripten_sleep