WASM compiler is crashing on Safari Technology Preview 43, works on Stable 11.0.2

Originator:steipete
Number:rdar://35349968 Date Originated:04-Nov-2017 11:15 AM
Status:Open Resolved:
Product:Safari Technology Preview Product Version:Release 43 (Safari 11.1, WebKit 13605.1.12)
Classification:Crash/Hang/Data Loss Reproducible:Always
 
Summary:
Open https://web-preview.pspdfkit.com/standalone/1 and observe Safari Technology Preview crashing,

Steps to Reproduce:
Open Website. Wait. Observe repeated crash until you see A problem repeatedly occurred with <br> “https://web-preview.pspdfkit.com/standalone/1”

Expected Results:
Website should render, WASM loads, PDF is rendered.

Actual Results:
Crash. I cannot figure out how to get a crash report for crashed tabs. There’s nothing in Console app and I can’t see any Apple documentation what to do specially. (https://webkit.org/getting-a-crash-log/ seems outdated, there’s no file in ~/Library/Logs/CrashReporter and there’s no Report Crash button)

Version:
Release 43 (Safari 11.1, WebKit 13605.1.12)

Notes:
WASM run works with ~latest few Safari (stable, including iOS 11 Mobile Safari), Mobile|Chrome, Firefox and Edge. Older browsers work as well, we fall back to asm.js so even IE 11 is happy :)

We had quite a few WASM crashes with Safari, mostly on iOS but also on macOS. Your team is always super responsive, thanks a lot! (Especially on the cascade of crashes we hit at WWDC with the ARM64 WASM compiler backend :) Would love to somehow add our renderer to your internal test suite, since it’s one of the first really large commercial WASM SDKs, and powers many companies/websites already. (peter@pspdfkit.com if you want to discuss this in more detail)

https://pspdfkit.com/blog/2017/webassembly-a-new-hope/
(Heads up: The blog post embeds our renderer, so it crashes as well :)

Comments

Apple got back to me! And asked me for a sysdiagnose.

WHYYYY


Please note: Reports posted here will not necessarily be seen by Apple. All problems should be submitted at bugreport.apple.com before they are posted here. Please only post information for Radars that you have filed yourself, and please do not include Apple confidential information in your posts. Thank you!