Opening DevTools (Inspector) sometimes causes Firefox to lag
Categories
(DevTools :: General, defect, P3)
Tracking
(Not tracked)
People
(Reporter: claas, Unassigned)
References
(Blocks 1 open bug)
Details
This has happened a few times in the last few weeks.
What were you doing?
I was looking at the landing page of AI Help (http://localhost:3000/en-US/plus/ai-help, a local webpack dev-server version of https://developer.mozilla.org/en-US/plus/ai-help) without being logged in.
Then I opened the DevTools using Right click > "Inspect" on an SVG element.
I'm not sure if the issue happened immediately, and I cannot reproduce it systematically, so it might have to do with me using "Inspect Accessibility properties" and using the "Check for issues" feature on the "Accessibility" tab, which I did prior to when the issue appeared.
What happened?
I noticed that reactions to mouse-overs and mouse clicks were slow, and clicking tabs (Console, Debugger) in the DevTools did not have any effect (apart from a delayed hover highlight).
When I closed the DevTools the issue went away.
What should have happened?
Opening the DevTools should not have had any noticeable impact on overall performance, and it should have been possible to change between tabs.
Anything else we should know?
Here's a profile, which I started as soon as I realized that Firefox was no longer reacting to my mouse properly, and then I clicked the DevTools tabs (which had no effect) during the profile: https://share.firefox.dev/3HYcweL
Enabled extensions:
Dictionnaire français dictionary 7.0b true fr-dicollecte@dictionaries.addons.mozilla.org
Add-ons Search Detection extension 2.0.0 true addons-search-detection@mozilla.com
Bing extension 1.6 true bing@search.mozilla.org
Decentraleyes extension 2.0.18 true jid1-BoFifL9Vbdl2zQ@jetpack
DuckDuckGo extension 1.4 true ddg@search.mozilla.org
Facebook Container extension 2.3.11 true @contain-facebook
Fakespot Fake Amazon Reviews and eBay Sellers extension 0.9.45 true {44df5123-f715-9146-bfaa-c6e8d4461d44}
Firefox DevTools ADB Extension extension 0.0.5 true adb@mozilla.org
Firefox Multi-Account Containers extension 8.1.3 true @testpilot-containers
Google extension 1.4 true google@search.mozilla.org
Redirector extension 3.5.3 true redirector@einaregilsson.com
uBlock Origin extension 1.55.0 true uBlock0@raymondhill.net
Web Archives extension 5.0.0 true {d07ccf11-c0cd-4938-a265-2a4d6ad01189}
Wikipedia (en) extension 1.3 true wikipedia@search.mozilla.org
Zoom Extension extension 2.1.52 true {bf855ead-d7c3-4c7b-9f88-9a7e75c0efdf}
System theme — auto theme 1.3 true default-theme@mozilla.org
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Comment 1•2 years ago
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Thanks for the report!
So, the profile doesn't show much information, but that may be normal since you started to profile once you experienced the lag?
I profiled the opening of the inspector on https://developer.mozilla.org/en-US/plus/ai-help but I don't see a big lag, and I didn't get much more when I recorded the "Check for issues" in the accessibility tab :/
Maybe this could only be visible with the local webpack server, since hot reload could come into play?
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Comment 2•2 years ago
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Not clear where this could come from, as Nicolas said the profile doesn't show much information.
Claas: did you experience the issue again since you filed the bug?
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Reporter | |
Comment 3•2 years ago
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Thank you both for looking into it.
Although I had the problem repeatedly 2-3 weeks ago, I haven't experienced it anymore since reporting it, so I'm going to close this issue.
Description
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