To reproduce, use iPad OS 13.4 beta 1 (iPad Pro 2018 model was used for this bug report):
1) Navigate with Safari to https://simulations.kognito.com/changetalk
2) Notice the crash immediately when attempting to load the wasm application
I have also hosted a "development build" of the wasm application referenced in 1) at: https://packages.kognito.com/ios_13_4_bug_report/ if you want to see a slightly more detailed error stack. I'm not sure if that extra information will be relevant or not.
For clarity, this wasm application currently works on iOS 13.3.x, Safari TP 100, and Chrome/Firefox/Edge so it would seem like a specific iOS/ARM problem. Let me know if I can provide any more information.
Tank you for the report! The title says "wasm applications", plural. Can you share more examples?
Sorry that was unintentionally misleading! All of our wasm applications fail to load under 13.4, but they all use mostly the same code base (so not surprising). Since they failed with the same error at the same place (similar error stacks), I figured just one link was sufficient. With a little bit of googling, I can confirm that at least some (most?) wasm applications do work with ios 13.4! :)
Sorry I can't be more useful here as we use Unity/Emscripten and the error stack generated doesn't seem to come from our code directly (it was triggered by either internal Unity or Emscpripten code). Therefore it's hard for me to say what exactly is going on that causes the error. However I'm pretty good at modifying Emscripten so if there's anything (or any clues you can give me) that I can do to make debugging this any easier just let me know!
Thanks for reporting this bug. We ended up fixing it in https://bugs.webkit.org/show_bug.cgi?id=207727.
*** This bug has been marked as a duplicate of bug 207727 ***