Error: "Cannot read property 'concat' of undefined"

[RealDrewKlayman]

Describe what you were doing when the bug occurred:

1. Ran Profiler
2. (Was On Flamegraph)

---

Please do not remove the text below this line

DevTools version: 4.10.0-11a2ae3a0d

Call stack: at updateTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:19691:53)
at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:19563:26)
at ProfilingCache_ProfilingCache.getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:20104:11)
at CommitFlamegraphAutoSizer (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:34150:33)
at Fh (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:12806:7)
at ni (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:13448:7)
at jk (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:16065:86)
at ik (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:15450:11)
at hk (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:15442:23)
at Zj (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:15426:5)

Component stack: at CommitFlamegraphAutoSizer (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:34133:50)
at div
at div
at div
at SettingsModalContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:28195:3)
at Profiler_Profiler (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:35761:50)
at ErrorBoundary_ErrorBoundary (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:29208:5)
at PortaledContent (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:29325:32)
at div
at div
at ProfilerContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:32923:3)
at TreeContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:24311:3)
at SettingsContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:24800:3)
at ModalDialogContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:29393:3)
at DevTools_DevTools (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:36196:3)

[eps1lon]

It doesn't look like this bug report has enough info for one of us to reproduce it.

Please provide a CodeSandbox (https://react.new/), a link to a repository on GitHub, or provide a minimal code example that reproduces the problem.

Here are some tips for providing a minimal example: https://stackoverflow.com/help/mcve

[bvaughn]

Likely related to issue #20173 (which also lacks a repro case)

[bvaughn]

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

[RealDrewKlayman]

With that in mind do I still need to repo this?

I'm having troubles figuring out which part of our code is causing this issue..

[bvaughn]

The more repros the better, since there could be more than one root bug that has a similar error message. 😄 But if you can't, I'll go with what I have

[sibelius]

is this related to react 17?

[RealDrewKlayman]

I am on React 17, but it works up until a certain point when clicking through the graph. I'm doing some more testing to figure out exactly where it occurs.

[bvaughn]

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

[RealDrewKlayman]

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

Yes, I am.

[TkDodo]

Yes, I also got the bug right now, React 17 and React.Lazy is also involved in case that helps :)

[bvaughn]

@RealDrewKlayman @TkDodo Can either of you share your repro with me? The one I have is sporadic- but I think I'm zeroing in on maybe fixing this. More data would be helpful

[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.