Claude Code v2.1.210 Fixes Worktree-Isolated Subagents Running Git-Mutating Commands Against the Main Repo

Claude Code Changelog·high signal

Shipped July 14, 2026, v2.1.210 fixes `isolation: 'worktree'` subagents running git-mutating commands against the main repository instead of their isolated worktree — the exact failure the isolation flag exists to prevent. Anyone using worktree isolation to fan out parallel agents safely was running without the guarantee they thought they had. Same release also fixes killed background sessions leaving a permanent `git worktree lock`.