ADR 0013: A place is a plain git worktree

Status: accepted · Date: 2026-10-13

Deciders: the user, reviewing sluice’s own configuration, 2026-10-13. Sources: agentplot/blueprints:design/sluice/requirements.md clauses 32 to 35, 83, 84, C.1; ADRs 0003, 0009, 0012; docs/plans/phase-1-integrations.md section 5.

Context and problem statement

ADR 0009 made the checkout method the one git setting, with worktrunk, plain git worktree and archive as its values, because the methods differ in what a place gets: a worktrunk place receives the repository’s worktrunk hooks and its wt step copy-ignored warming. Since then a run is held by an executor that confines it (ADR 0012), and a place takes its build cache from what its branch’s policy declares (35, [[checkout.cache]]). What does a place still need from anything but git worktree?

Considered options

1. Keep three methods: worktrunk, git worktree, and archive once built.
2. One method, a detached git worktree with no hook, and no setting.

Decision outcome

Option 2. A worktrunk place gave three things. Its pre-start hooks are the candidate’s own code run with the user’s full permissions, outside the executor that every check runs under, so a sandboxed gate would be bypassed by the setup it trusts least. Its warming is the policy’s cache now, keyed by content and saved only from a passed candidate, where worktrunk’s copies whatever the primary worktree holds. Its path, beside the user’s worktrees, puts a place on whatever disk the user’s template names, so saving a cache becomes a copy rather than a rename, and its sluice/try/… branch shows in every session’s wt list. What a check needs before it runs is the toolchain step and the check’s own dependencies, both run as a CI job runs its setup steps. Archive, designed and never built, is dropped too: a place with no git metadata would keep a run off the repository, which the executor already does, while the task runner’s affected query needs that metadata and saving a cache from a place outside the repository’s directory becomes a copy.

The place seam keeps its interface (ADR 0003) with this one profile, which rule core.3 requires an ADR for: this is it. A container place, should one be needed, is the container executor’s, not a second checkout.

Consequences

• C.1 of the statement names the git worktree and the container; worktrunk is the driver alone (C.4).
• [checkout] names no method. A policy that still says method = "git-worktree", as an older revision of a branch does, is read as before (rule core.15), and any other method is refused with the reason.
• .worktreeinclude and wt step copy-ignored remain the repository’s own, for worktrees people make; no place reads them.
• Supersedes ADR 0009’s checkout setting; its branch operations stand.