How do I stop the javascript debugger, console, and performance profiler from freezing during javascript execution so I can troubleshoot the slowdown?

I’m trying to debug a userscript that seems to be going into an endless loop on just one certain page. The page freezes and never finishes drawing and the script never finishes running.

However, while it’s in the loop, the debugger, console, and performance profiler all stop working, as if they’re waiting for it to finish. Those are the tools I need to see what it’s so busy doing that it never finishes… if they freeze, I have no way of troubleshooting. How do I get the developer tools not to freeze during script execution?

Sounds like something is taking over your main thread. Could you help us record a performance profile using https://developer.mozilla.org/en-US/docs/Mozilla/Performance/Profiling_with_the_Built-in_Profiler ?

Sure: https://perfht.ml/2ZaNMeG Thanks.