Bump yjs to 13.6.30 (fixes GC crash in applyUpdate)#566
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The bundled yjs 13.6.20 has a bug in sortAndMergeDeleteSet that mutates DeleteItem.len in place (yjs/yjs#767), corrupting shared references used by tryGcDeleteSet. This causes findIndexSS to throw "Unexpected case" during document sync GC. Fixed in yjs 13.6.30. Also picks up yjs 13.6.25/26 fixes for iterateDeletedStructs bounds checking. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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…s 13.6.20 Set `bundled: true` for yjs and y-protocols in both collaboration-extension and docprovider-extension sharedPackages config. Without this, the extensions declare yjs as `bundled: false, singleton: true`, meaning they consume whatever version JupyterLab core provides (13.6.20) rather than providing the fixed 13.6.30 to the Module Federation share scope. With `bundled: true`, webpack includes yjs 13.6.30 in the extension build and offers it to the singleton scope. Since 13.6.30 > 13.6.20 and both satisfy ^13.5.40, Module Federation picks 13.6.30 for all consumers, fixing the GC crash in sortAndMergeDeleteSet (yjs/yjs#767). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
…tall) The hatch-jupyter-builder hook has skip-if-exists for the labextension static assets. Without these committed, pip install tries to rebuild from source which requires Node.js — unavailable in the notebook Docker image. Force-adding these gitignored files lets pip install use the pre-built JS directly. Built with yjs 13.6.30 and bundled:true, so Module Federation provides 13.6.30 to the singleton scope. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
krassowski
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Apr 10, 2026
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This PR cannot be merged as it includes files which should not have been committed, and extensive changes to yarn.lock beyond what is necessary. I am happy to merge a PR bumping yjs version but it shuld be a minimal self-contained change.
krassowski
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This commits generated files which should not be committed. It also makes changes to bundling without explanation and containe unnecessary changes in the yarn lock file.
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Summary
Bumps yjs from 13.6.20 to 13.6.30 and lib0 from 0.2.98 to 0.2.99 in
yarn.lock. The semver range (^13.5.40) already allows this — only the lockfile pin changes.This fixes a crash during
applyUpdate→tryGcDeleteSet→findIndexSSthat throws "Unexpected case" on every page load when collaboration is enabled.Three bugs in yjs < 13.6.25 contribute:
iterateDeletedStructsiterates past known struct bounds (no clock guard)iterateDeletedStructssortAndMergeDeleteSetmutatesDeleteItem.lenin place instead of creating a new object (mergeDeleteSetsmutates delete sets, causes snapshot comparison to fail yjs/yjs#767), corrupting shared references used by GCHow we found this
We decompiled the minified yjs bundle in JupyterLab's static assets and traced the error through
findIndexSS→replaceStruct→Item.gc→ContentType.gc(the full GC hierarchy). The old buggy patternleft.len = math.max(left.len, ...)was present at offset 30350 in the bundle, matching the pre-13.6.30 source.Reproduction
Any JupyterLab instance with
jupyter-collaborationenabled that has accumulated deleted items in a Yjs document will hit this on page load during the initial document sync. The error is caught by the docprovider (console.error("Caught error while handling a Yjs update", e)) so it doesn't crash, but it breaks document sync for the affected document.Test plan
jlpm test— 16 JS tests passpytest tests/— 52 Python tests passjlpm build— all 5 packages build successfully