@@ -1,13 +1,16 @@
 ---
 subject: design
-status: active
+status: landed
 ---
 
 # Build cost, foreign toolsets, the build-plugin architecture and the library surface: engine, plugin and index design (#734)
 
-**Status:** active, revision 5 (2026-09-28). The design is settled (§11); §13
+**Status:** landed, revision 5 (2026-09-28). The design is settled (§11); §13
 divides it into tasks per repository, with their dependencies and criteria, and
-records their implementation.
+records their implementation. E2 to E6 were released in 2026.9.28.3 and the
+plugin items in mcpp.plugins 0.17.0. E1 is replaced by
+`2026-09-29-workspace-build-graph-design.md`, released as 2026.9.29.1 to
+2026.9.29.4.
 
 - **Revision 1** proposed engine items E1 to E6 and plugin items P1 to P5.
 - **Revision 2** records the first review:
 
@@ -1,11 +1,13 @@
 ---
 subject: design
-status: active
+status: landed
 ---
 
 # The workspace as the unit of build: one graph per configuration, one scheduler, product directories, and a reusable graph module
 
-- Status: design, agreed; implementation in progress (revision 4)
+- Status: landed (revision 4). Released as 2026.9.29.1 (#738); corrections in
+  2026.9.29.2 (#739), 2026.9.29.3 (#740) and 2026.9.29.4 (#741), recorded in
+  section 17.1
 - Date: 2026-09-29
 - Origin: the #734 validation on a five-member Windows workspace (the validation
   project's pull request), and the discussion that followed it
 
@@ -30,9 +30,9 @@ Records that declare one. Everything else is listed by date below.
 
 ### design
 
-- [The workspace as the unit of build: one graph per configuration, one scheduler, product directories, and a reusable graph module](2026-09-29-workspace-build-graph-design.md) — active
+- [The workspace as the unit of build: one graph per configuration, one scheduler, product directories, and a reusable graph module](2026-09-29-workspace-build-graph-design.md) — landed
 - [An ecosystem design for mcpp and xlings: one authority per fact, and the work that follows from it](2026-09-28-ecosystem-design-and-optimisation-plan.md) — landed
-- [Build cost, foreign toolsets, the build-plugin architecture and the library surface: engine, plugin and index design (#734)](2026-09-28-build-cost-foreign-toolsets-and-library-surface-design.md) — active
+- [Build cost, foreign toolsets, the build-plugin architecture and the library surface: engine, plugin and index design (#734)](2026-09-28-build-cost-foreign-toolsets-and-library-surface-design.md) — landed
 - [The compile database, `emit build-database`, and #701/#702: triage against the specifications, and one design](2026-09-26-compile-database-and-issue-699-design.md) — landed
 - [Issues #693 to #696: triage against mcpp's contracts, and one repair plan](2026-09-25-issues-693-696-triage-and-repair-plan.md) — landed
 - [Workspace inheritance, flag scoping and the published form: a unified repair plan (#690)](2026-09-25-issue-690-workspace-build-inheritance-consistency.md) — landed
@@ -108,10 +108,10 @@ Records that declare one. Everything else is listed by date below.
 
 ### 2026-09
 
-- [The workspace as the unit of build: one graph per configuration, one scheduler, product directories, and a reusable graph module](2026-09-29-workspace-build-graph-design.md) — active
+- [The workspace as the unit of build: one graph per configuration, one scheduler, product directories, and a reusable graph module](2026-09-29-workspace-build-graph-design.md) — landed
 - [Two days of mcpp and xlings: a review of what merged, what is known, and what is open](2026-09-28-ecosystem-review-of-two-days-of-mcpp-and-xlings.md) — active
 - [An ecosystem design for mcpp and xlings: one authority per fact, and the work that follows from it](2026-09-28-ecosystem-design-and-optimisation-plan.md) — landed
-- [Build cost, foreign toolsets, the build-plugin architecture and the library surface: engine, plugin and index design (#734)](2026-09-28-build-cost-foreign-toolsets-and-library-surface-design.md) — active
+- [Build cost, foreign toolsets, the build-plugin architecture and the library surface: engine, plugin and index design (#734)](2026-09-28-build-cost-foreign-toolsets-and-library-surface-design.md) — landed
 - [Eight reports after 2026.9.27.1: implementation plan](2026-09-27-eight-reports-implementation-plan.md) — active
 - [Eight reports after 2026.9.27.1: what each one is, where it belongs, and one optimisation plan](2026-09-27-eight-reports-by-home-and-one-optimisation-plan.md) — active
 - [The compile database, `emit build-database`, and #701/#702: triage against the specifications, and one design](2026-09-26-compile-database-and-issue-699-design.md) — landed