Objective
Every new worktree starts with an empty build directory. On 2026-09-19, with kache at an 89% hit rate, the first codex-core test build in a fresh worktree still took over ten minutes, and each worktree's build directory is about 60 GB.
Finish Line
Creating a worktree with dev-worktree yields a build directory warm enough that the first focused test run starts in under two minutes, without sharing a mutable target directory between worktrees.
Current Status
State: parked outside the milestones.
Parked until fresh-start work records at least two cold first builds of a new worktree that take more than 10 minutes and delay milestone work. The fix belongs with the owner of the dev-worktree host tooling, not in this repository.
Next action: none until then.
Blocked by: no native issue blocker.
Last verified: 2026-09-26 backlog reconciliation against the merged DIRECTION.md.
Scope
- In: an APFS-cloned template target created from a recent main build and cloned by
dev-worktree (clones are free and stay independent, which respects the no-shared-mutable-target rule); or whatever the measurement shows is the real cost.
- Out: sharing one target directory between worktrees; changes to kache itself.
Acceptance Criteria
Relationships
Related: #942 (dogfood pivot), milestone "Codex Lab Fast Feedback Loop" (#638, #639, #640, #814). Related: #855 (target retention), #853 (latency and disk budgets).
Validation
Time from dev-worktree to first passing focused test, before and after.
Decisions
None yet.
Open Questions
Whether a cloned target survives the absolute-path and fingerprint checks cargo applies when the workspace path differs.
Objective
Every new worktree starts with an empty build directory. On 2026-09-19, with kache at an 89% hit rate, the first
codex-coretest build in a fresh worktree still took over ten minutes, and each worktree's build directory is about 60 GB.Finish Line
Creating a worktree with
dev-worktreeyields a build directory warm enough that the first focused test run starts in under two minutes, without sharing a mutable target directory between worktrees.Current Status
State: parked outside the milestones.
Parked until fresh-start work records at least two cold first builds of a new worktree that take more than 10 minutes and delay milestone work. The fix belongs with the owner of the
dev-worktreehost tooling, not in this repository.Next action: none until then.
Blocked by: no native issue blocker.
Last verified: 2026-09-26 backlog reconciliation against the merged DIRECTION.md.
Scope
dev-worktree(clones are free and stay independent, which respects the no-shared-mutable-target rule); or whatever the measurement shows is the real cost.Acceptance Criteria
dev-worktree.Relationships
Related: #942 (dogfood pivot), milestone "Codex Lab Fast Feedback Loop" (#638, #639, #640, #814). Related: #855 (target retention), #853 (latency and disk budgets).
Validation
Time from
dev-worktreeto first passing focused test, before and after.Decisions
None yet.
Open Questions
Whether a cloned target survives the absolute-path and fingerprint checks cargo applies when the workspace path differs.