Error: "Commit tree does not contain fiber 1527. This is a bug in React DevTools."

[WilliamCSA04]

Describe what you were doing when the bug occurred:

1. Go to profile tag
2. Click to record
3. After stop recording, click on any commits.

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Please do not remove the text below this line

DevTools version: 4.9.0-75726fadfd

Component stack: CommitFlamegraphAutoSizer@moz-extension://7ef91e4d-0a91-434a-b6fa-c2646d78406c/build/main.js:33986:50
div
div
div
SettingsModalContextController@moz-extension://7ef91e4d-0a91-434a-b6fa-c2646d78406c/build/main.js:28047:1
Profiler_Profiler@moz-extension://7ef91e4d-0a91-434a-b6fa-c2646d78406c/build/main.js:35614:50
ErrorBoundary_ErrorBoundary@moz-extension://7ef91e4d-0a91-434a-b6fa-c2646d78406c/build/main.js:29061:5
PortaledContent@moz-extension://7ef91e4d-0a91-434a-b6fa-c2646d78406c/build/main.js:29178:27
div
div
ProfilerContextController@moz-extension://7ef91e4d-0a91-434a-b6fa-c2646d78406c/build/main.js:32775:1
TreeContextController@moz-extension://7ef91e4d-0a91-434a-b6fa-c2646d78406c/build/main.js:24163:1
SettingsContextController@moz-extension://7ef91e4d-0a91-434a-b6fa-c2646d78406c/build/main.js:24652:1
ModalDialogContextController@moz-extension://7ef91e4d-0a91-434a-b6fa-c2646d78406c/build/main.js:29245:1
DevTools_DevTools@moz-extension://7ef91e4d-0a91-434a-b6fa-c2646d78406c/build/main.js:36048:1

[bvaughn]

I thought this issue was a duplicate and already resolved, but I believe I was mistake. Re-opening.

Repro info would be very helpful, @WilliamCSA04.

[WilliamCSA04]

I thought this issue was a duplicate and already resolved, but I believe I was mistake. Re-opening.

Repro info would be very helpful, @WilliamCSA04.

I'm no longer getting this error. I did try just now to reproduce it and I could not, maybe it was fixed? Not sure, but it was just like I described before. Once you were on the profile tab, you clicked on Start profiling and after stopped profiling, you went to that vertical bars and click on any of them.

[bvaughn]

Yeah, I think the repro case would involve profiling some specific kind of app or interaction with an app. That's the part I'm missing. Starting and stopping the profiler is something I do all the time and I haven't seen the bug we're talking about unfortunatey.

[bvaughn]

I think the underlying cause of this is the same as #16493 which I now have a repro for.

[bvaughn]

Quick question for folks who are seeing this bug in your app: Are you using the React.Lazy component?

And can any of you share a repro with me?

[bvaughn]

If you can repro this yourself, would any of you be willing to try this build of DevTools and let me know if it fixes the issue?

https://github.com/facebook/react/files/5644517/ReactDevTools.zip

I have reason to suspect that maybe I've fixed at least one case of this already (recently, unreleased) and I'm wondering if that's why I'm having trouble reproing.

[bvaughn]

I believe this issue was fixed via PR #20362. It has now been published as v4.10.1 and should be available shortly.

Please let me know if you still see the issue after installing that version and I can re-open and investigate further.

[bvaughn]

@WilliamCSA04 This error remains the highest reported DevTools bug but we still don't have a repro case so that I can fix it. Do you remember how to repro the error you saw above? Can you share the steps with me if so? It would be very helpful! Thank you 🙇🏼