Distillation

Date: Sep 8, 2026

• 🔴 (12:01) User stated that in the jj workspace add implementation, Git is never asked to resolve a revision; therefore jj workspace add -r <rev> produces Git HEAD matching the requested revision rather than the main workspace’s HEAD.
• 🟢 (12:01) Tool output: jj-vcs/jj PR #9941, “workspace add/forget: bridge jj workspaces with git worktrees,” was merged into main on Sep 4, 2026 via merge-queue commit 2133040a8b99df306b3b6a199608b5ae669ae8a6; all 35 checks passed.
• 🟢 (12:01) Tool output: PR #9941 adds jj workspace add --colocate and --no-colocate. Without either flag, it creates a Git worktree only if the current workspace is colocated and git.colocate = true; non-colocated repository behavior is unchanged.
• 🟢 (12:01) Tool output: PR #9941 creates colocated worktrees using git worktree add --orphan, allowing jj to populate the working copy; it creates a random unborn branch because destination-derived names could collide with exported bookmarks, then repoints HEAD to refs/jj/root so git commit cannot create an unrequested branch.
• 🟢 (12:01) Tool output: PR #9941 changes jj workspace forget to remove an associated Git worktree by deleting its .git gitlink and pruning .git/worktrees/ metadata while preserving the workspace directory contents; it raises MINIMUM_GIT_VERSION from 2.41.0 to 2.42.0 because git worktree add --orphan requires Git 2.42.
• 🟢 (12:01) Tool output: PR #9982 was identified as the second PR in the series for colocating existing jj workspaces.