Claude Code: Long-Session Reliability — /compact Deadlock Fix and Scroll Performance

The /compact Deadlock: Fixed

The /compact command in Claude Code serves a critical role in long coding sessions: when a conversation grows large, running /compact condenses the transcript into a compact summary, freeing up context window space so the session can continue without starting from scratch. The catch is that the command itself requires available context window capacity to execute — and in the exact moment it was needed most, there was no room left.

Claude Code v2.1.85 fixes this deadlock. Previously, users who let a session grow until the context window was fully saturated would encounter a "context exceeded" error when attempting to run /compact. The fix ensures that /compact can execute even in fully-saturated sessions, eliminating the frustrating scenario where the only tool available to rescue a session was itself blocked by the session's size.

This bug was well-documented in the community, with GitHub issues #23047 and #23751 among the reports that tracked the problem. The fix closes a reliability gap that affected any developer running extended, context-heavy sessions — precisely the users doing the most complex work with the tool.

Replacing the Layout Engine for Better UI Performance

Beyond the deadlock fix, v2.1.85 swaps out Claude Code's WASM-based yoga-layout engine in favor of a pure TypeScript implementation. The yoga-layout library is used internally for UI layout calculations — determining how components like the transcript pane, tool output panels, and input area are arranged and rendered.

The WASM implementation, while functionally correct, introduced overhead that caused noticeable stutter during compaction and degraded scroll performance in large transcripts. When a session accumulated hundreds of tool calls, file reads, and assistant responses, scrolling through the transcript would feel sluggish.

The TypeScript replacement eliminates this bottleneck. Compaction is now visually smooth, and scroll performance in large transcripts is substantially improved. For developers who regularly reach late-session complexity — the exact users most likely to benefit from /compact — this is a meaningful quality-of-life improvement.

Faster @-Mention Autocomplete on Large Repositories

File path autocomplete when typing @ to reference a file now resolves faster on large repositories. The optimization reduces the latency between starting to type a path and seeing completions appear, which adds up across a full development session where file references are frequent.

Summary

Claude Code v2.1.85 is a focused reliability and performance release. The /compact deadlock fix closes an important gap for long-session users, the layout engine replacement improves rendering performance where it matters most, and the autocomplete speed improvement rounds out the release. No new features ship in this version — the focus is squarely on making existing workflows more reliable.