An error occurred in Firefox Profiler

[MHanak1]

pressingL_CTRL + [ causes the tool to crash.

error: Error: There was an unhandled case for the value: "undefined"
browser: Mozilla Firefox 133.0

┆Issue is synchronized with this Jira Task

[julienw]

Hey, thanks for the issue!
Can you please give some more precisions about your environment, especially about your operating system?
Can you also please give some more information about the steps you did before that?
Is it safe to say that pressing L_CTRL + [ was a way for you to go back? Do you have the same issue when you press the "back" button instead?
Is it happening all the time you're pressing these keys, or did it happen just once?
Thanks

[MHanak1]

Hey, thanks for the issue! Can you please give some more precisions about your environment, especially about your operating system? Can you also please give some more information about the steps you did before that? Is it safe to say that pressing L_CTRL + [ was a way for you to go back? Do you have the same issue when you press the "back" button instead? Is it happening all the time you're pressing these keys, or did it happen just once? Thanks

System: OS: Arch Linux x86_64 Kernel: Linux 6.12.1-arch1-1

I've managed to pin down the source of this issue to the ClearURLs addon

Steps to reproduce:

1. Install the ClearURLs addon
2. open the Firefox Devtools "performance" start and stop the recording
3. once taken to the Firefox profiler switch from the "call tree" tab to any other tab
4. press L_CTRL + [ (or press the "back" button, i wasn't aware that it was a browser shortcut)
5. the profiler should crash (it does reliably in my browser)

[julienw]

Ah I see!
I can reproduce as well. I had this extension but disabled it because of all the problems in various websites. The problematic setting is the one fiddling with the history:

I'm not fully sure what the option does, but if you disable this, then the profiler UI will work fine. We're indeed using |replaceState and pushState a lot.
It's too bad the extension doesn't have an exclusion list.

Please also note that Firefox now has a native feature to copy URLs without their tracking parameters, see https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop#w_copy-without-site-tracking for more information. So the addon might not be necessary anymore depending on what you're looking for.