React warning when navigating between templates index and template screens in the Site Editor

[tellthemachines]

Description

When switching between the templates index and various templates in the Site Editor, the following warning appears in the console:

Warning: Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in a useEffect cleanup function.
    at Items (http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:11909:5)
    at BlockListItems
    at BlockContextProvider (http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:9975:5)
    at UncontrolledInnerBlocks (http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:24669:5)
    at div
    at GroupEdit (http://localhost:8888/wp-content/plugins/gutenberg/build/block-library/index.min.js?ver=08946c36892a0c5956f1ef3ece66476d:17637:5)
    at Edit (http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:10645:5)
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:39877:11
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:40085:96
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:41662:105
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:44329:116
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:42132:102
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:43371:11
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-library/index.min.js?ver=08946c36892a0c5956f1ef3ece66476d:38253:5
    at http://localhost:8888/wp-content/plugins/gutenberg/build/edit-post/index.min.js?ver=346c8bb5d3d0fa51a7237483939ed242:8086:7
    at http://localhost:8888/wp-content/plugins/gutenberg/build/data/index.min.js?ver=37cee40df377d47ae5f591bf76a3d37d:1895:82
    at http://localhost:8888/wp-content/plugins/gutenberg/build/data/index.min.js?ver=37cee40df377d47ae5f591bf76a3d37d:2016:77
    at <anonymous> (http://localhost:8888/wp-content/plugins/gutenberg/build/compose/index.min.js?ver=57c5ad56207b3cb409dcfb54994cf1e4:2277:10)
    at FilteredComponentRenderer (http://localhost:8888/wp-content/plugins/gutenberg/build/components/index.min.js?ver=46c12e161c55d5bd0649ba57585881a5:70552:9)
    at BlockEdit (http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:10714:5)
    at div
    at BlockCrashBoundary (http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:11162:5)
    at BlockListBlock (http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:11556:5)
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:39927:5
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:40419:5
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:41499:5
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:42847:88
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:44342:51
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:42176:99
    at http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:43390:5
    at FilteredComponentRenderer (http://localhost:8888/wp-content/plugins/gutenberg/build/components/index.min.js?ver=46c12e161c55d5bd0649ba57585881a5:70552:9)
    at http://localhost:8888/wp-content/plugins/gutenberg/build/compose/index.min.js?ver=57c5ad56207b3cb409dcfb54994cf1e4:2225:8
    at http://localhost:8888/wp-content/plugins/gutenberg/build/data/index.min.js?ver=37cee40df377d47ae5f591bf76a3d37d:1895:82
    at http://localhost:8888/wp-content/plugins/gutenberg/build/data/index.min.js?ver=37cee40df377d47ae5f591bf76a3d37d:2016:77
    at <anonymous> (http://localhost:8888/wp-content/plugins/gutenberg/build/compose/index.min.js?ver=57c5ad56207b3cb409dcfb54994cf1e4:2269:12)
    at Items (http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:11909:5)
    at BlockListItems
    at BlockContextProvider (http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a9563508:9975:5)
    at UncontrolledInnerBlocks (http://localhost:8888/wp-content/plugins/gutenberg/build/block-editor/index.min.js?ver=17e0e3cbf54f0fe79f85d3a1a95

Step-by-step reproduction instructions

1. Go to the Site Editor;
2. Open the left hand sidebar and navigate to Templates index;
3. Navigate to one of the templates;
4. Go back and forth between index and templates until error shows in console.

Screenshots, screen recording, code snippet

No response

Environment info

Latest Gutenberg trunk running on WP 5.9-beta4-52408.

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[Mamaduka]

I'm removing this issue from WP 5.9 project board since we're already in the RC phase.

We can probably ignore most of the "Can't perform a React state update on an unmounted component" warnings. React 18 is removing them - reactwg/react-18#82. But I think it would be nice to fix this anyways.

[youknowriad]

I haven't been able to reproduce this issue recently. It might have been fixed.