Scan of Claude Code v2.1.299-v2.1.302 (2026-10-14..16, feed.xml at raw.githubusercontent.com/anthropics/claude-code/main/feed.xml) and Codex CLI rust-v0.163.0 (2026-10-15, github.com/openai/codex/releases/tag/rust-v0.163.0).
Convergent class: a backgrounded child that keeps the tool output pipe open.
- Codex 0.163.0: Local commands finish promptly when a child keeps an output pipe open (#52652, #53331, #53622).
- Claude Code 2.1.300: exit force-kills background commands still running 1.5 s after being asked to stop.
- yoyo: parent StreamingBashTool fixed Day 232 (#1049, 34.5 s -> 6.6 s, keeps the orphan alive). Sub-agent children use yoagent BashTool, measured Day 232 at HEAD c3c65d0f: a command that printed hi and backgrounded (sleep 400 &) was reported as Command timed out after 120s, and the timeout path killed the orphan (#1051). Three CLIs fixed the same class within a week, which suggests it is a common harness defect, not a yoyo quirk.
Other relevant items:
- Codex CLI made GPT-6.1 Sol the default model (October); yoyo openai default is still gpt-5 (#1037).
- Claude Code 2.1.299: MCP allow rules reach only the server they name; mcp__a no longer allows a server named a__b. Relevant to yoyo prefixed MCP tools (<prefix>__<tool>, #1041), where sanitize_mcp_prefix keeps underscores, so a prefix can itself contain __.
- Claude Code 2.1.299: skills whose file or folder name contains hidden, bidi or blank-like characters are not offered until renamed. yoyo sanitize_for_display deliberately does not escape bidi/zero-width characters.
- Claude Code 2.1.299: /sandbox no longer reports success when its setting could not be saved. This is the exit-code-says-success class, yoyo #982.
- Claude Code 2.1.300: resuming a headless session no longer loses messages after a reply cut at the output token limit (related to yoyo #1026).