An older build request never replaces a newer one's artifact

Builds of one module in flight together finish in any order, and the mesh
took whatever it heard last as what the module is: RegisterModule overwrote
the module's manifest unconditionally, and Held/BuiltAgainst/ReadRepositories
ordered builds by when they were recorded. A postgres build asked before the
mesh-tools runtime fix finished after the one asked after it, and the next
push deployed the stale image (novox/hq issue 219).

A build is now ordered by when it was asked, read from the build-<nanos> id
the controller writes: build.asked and module.built_asked (migration 0055).
A registration from an earlier request than the module's current one is
recorded and refused as superseded. A plan takes as its outcome only a build
asked at or after its own ask, so an earlier plan's leftover build cannot
settle a later plan. Ids of any other shape keep the old order.

cmd/mesh-controller/build.go

@@ -148,6 +148,11 @@ func buildFrom(result link.BuildResult) inventory.Build {
 		// rebuild the graph rather than a list of names.
 		Path: result.Path,
 	}
+	// When it was asked, which is what orders it against another build of the same module
+	// (novox/hq 04-ISSUES/219) — not when it was heard.
+	if asked, ok := link.BuildAskedAt(result.ID); ok {
+		kept.Asked = asked
+	}
 	for _, ref := range result.Against {
 		kept.Against = append(kept.Against, catalogue.Recorded(ref))
 	}
@@ -409,7 +414,7 @@ func buildOne(ctx context.Context, source buildSource, path, ref string, wait ti
 	// Correlated by something the control plane makes, not by the module's name: two builds of one
 	// module can be in flight, and the second answer is not the first one's.
 	request := link.BuildRequest{
-		ID:         fmt.Sprintf("%s-%d", "build", time.Now().UnixNano()),
+		ID:         link.NewBuildID(time.Now()),
 		Repository: repository,
 		Path:       path,
 		Ref:        ref,
@@ -526,6 +531,9 @@ func takeIn(ctx context.Context, inv *inventory.Inventory, result link.BuildResu
 		BuiltFrom: result.Commit, Head: result.Commit,
 		// What it stood on, so registration can judge a built manifest's base (to-be 38 WP2.4).
 		Against: kept.Against,
+		// When it was asked, so an older request heard later does not replace a newer one
+		// (novox/hq 04-ISSUES/219).
+		Asked: kept.Asked,
 	}
 	if result.Source != nil && result.Source.Seat != "" {
 		recorded.Repository, recorded.Seat = result.Source.Repository, result.Source.Seat
@@ -544,6 +552,10 @@ func takeIn(ctx context.Context, inv *inventory.Inventory, result link.BuildResu
 			result.On, result.Repository, short(result.Commit), err)
 	}
 	if err := inv.RegisterModule(ctx, manifest, recorded); err != nil {
+		if errors.Is(err, inventory.ErrSuperseded) {
+			return manifest, kept, fmt.Errorf("%s built %s (%s), recorded and not registered: %w",
+				result.On, manifest.Module, short(result.Commit), err)
+		}
 		return manifest, kept, err
 	}
 	return manifest, kept, nil
@@ -573,7 +585,7 @@ func buildAndShow(ctx context.Context, source buildSource, path, ref string, wai
 	defer ask.Close()
 
 	result, err := ask.Submit(ctx, link.BuildRequest{
-		ID:         fmt.Sprintf("%s-%d", "build", time.Now().UnixNano()),
+		ID:         link.NewBuildID(time.Now()),
 		Repository: repository, Path: path, Ref: ref,
 		Held: heldBy(ctx), Seats: seatBases(ctx),
 	}, wait)

cmd/mesh-controller/build_test.go

@@ -2,9 +2,12 @@ package main
 
 import (
 	"encoding/json"
+	"errors"
 	"strings"
 	"testing"
+	"time"
 
+	"github.com/novox/mesh-controller/internal/inventory"
 	"github.com/novox/mesh-controller/internal/link"
 )
 
@@ -100,3 +103,50 @@ func TestABuildAtACommitKeepsTheBranchTheModuleFollows(t *testing.T) {
 		t.Errorf("a module first built at a commit follows %q, want the default branch", src.Ref)
 	}
 }
+
+// novox/hq 04-ISSUES/219: an older request heard after a newer one is recorded and not registered,
+// so a push sends what the newer request built.
+func TestAnOlderBuildHeardLaterDoesNotReplaceTheNewer(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	older := time.Date(2026, 10, 3, 21, 33, 45, 0, time.UTC)
+	newer := time.Date(2026, 10, 3, 21, 51, 57, 0, time.UTC)
+	result := func(asked time.Time, image string) link.BuildResult {
+		manifest, _ := json.Marshal(map[string]any{"module": "postgres", "version": image})
+		return link.BuildResult{ID: link.NewBuildID(asked), Repository: "http://forge.internal:20000/novox/mesh-catalog.git",
+			Path: "modules/postgres", Ref: "main", On: "anchor", Commit: "efff5415", Manifest: manifest,
+			Source: &link.SourceOnSeat{Seat: "git", Repository: "novox/mesh-catalog"}}
+	}
+	if _, _, err := takeIn(ctx, open.inventory, result(newer, "4bcd5f73")); err != nil {
+		t.Fatal(err)
+	}
+	_, _, err := takeIn(ctx, open.inventory, result(older, "0ab07fa9"))
+	if !errors.Is(err, inventory.ErrSuperseded) {
+		t.Fatalf("the older request's outcome was taken in as current: %v", err)
+	}
+	shelf, err := open.inventory.Catalogue(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := shelf["postgres"].Version; got != "4bcd5f73" {
+		t.Errorf("postgres is %q; want the newer request's 4bcd5f73", got)
+	}
+	if builds, _ := open.inventory.Builds(ctx, "postgres", 5); len(builds) != 2 {
+		t.Errorf("the late build was not recorded: %v", builds)
+	}
+}
+
+func TestABuildIDSaysWhenItWasAsked(t *testing.T) {
+	at := time.Date(2026, 10, 3, 21, 51, 57, 392539762, time.UTC)
+	if got, ok := link.BuildAskedAt(link.NewBuildID(at)); !ok || !got.Equal(at) {
+		t.Errorf("read back %v %v; want %v", got, ok, at)
+	}
+	if got, ok := link.BuildAskedAt("build-1791064317392539762"); !ok || got.Format(time.TimeOnly) != "21:51:57" {
+		t.Errorf("the incident's id reads as %v %v", got, ok)
+	}
+	for _, id := range []string{"b-1", "build-2", "build-", "build-x", ""} {
+		if _, ok := link.BuildAskedAt(id); ok {
+			t.Errorf("%q read as a request time", id)
+		}
+	}
+}

cmd/mesh-controller/main.go

@@ -8,6 +8,7 @@ package main
 
 import (
 	"context"
+	"errors"
 	"flag"
 	"fmt"
 	"os"
@@ -253,25 +254,34 @@ func parseAround(set *flag.FlagSet, args []string) ([]string, error) {
 // became of a build nobody was watching.
 func (b builds) Built(ctx context.Context, result link.BuildResult) error {
 	manifest, _, err := takeIn(ctx, b.inv, result)
+	// When it was asked, so a plan takes as its outcome only a build asked for it or after it
+	// (novox/hq 04-ISSUES/219). Zero when the id does not say.
+	asked, _ := link.BuildAskedAt(result.ID)
 	switch {
 	case err != nil && result.Failed != "":
 		fmt.Printf("%s: %v\n", result.ID, err)
 		if result.Module != "" {
-			planBuilt(ctx, b.open, result.Module, result.Commit, result.Failed)
+			planBuilt(ctx, b.open, result.Module, result.Commit, result.Failed, asked)
 		} else {
 			planFailedBuild(ctx, b.open, result)
 		}
 		return nil
+	case errors.Is(err, inventory.ErrSuperseded):
+		// Not a failure: the module is already at what a later request built. A plan that asked
+		// before that later request is answered by it; one that asked after it ignores this.
+		fmt.Printf("%s: %v\n", result.ID, err)
+		planBuilt(ctx, b.open, manifest.Module, result.Commit, "", asked)
+		return nil
 	case err != nil:
 		fmt.Printf("%s: heard and recorded, and not registered: %v\n", result.ID, err)
 		if manifest.Module != "" {
-			planBuilt(ctx, b.open, manifest.Module, result.Commit, err.Error())
+			planBuilt(ctx, b.open, manifest.Module, result.Commit, err.Error(), asked)
 		}
 		return nil
 	}
 	fmt.Printf("%s: %s %s registered, built on %s from %s\n",
 		result.ID, manifest.Module, manifest.Version, result.On, short(result.Commit))
 	saysWhenThePolicyActs(ctx, b.inv, manifest.Module)
-	planBuilt(ctx, b.open, manifest.Module, result.Commit, "")
+	planBuilt(ctx, b.open, manifest.Module, result.Commit, "", asked)
 	return nil
 }

cmd/mesh-controller/release_plan.go

@@ -288,7 +288,13 @@ func askTier(ctx context.Context, inv *inventory.Inventory, p *inventory.Plan) e
 
 // planBuilt marks a module built (or failed) in every open plan whose current tier holds it, and
 // advances what that completes. Called from the daemon's take-in of every outcome.
-func planBuilt(ctx context.Context, open *stores, module, commit, failed string) {
+//
+// **Only a build asked at or after the plan's ask is its outcome** (novox/hq 04-ISSUES/219). Two
+// plans a few minutes apart both ask for a module; the earlier plan's build, finishing late, is not
+// the later plan's answer — it stood on the bases from before the later plan's merge, and taking it
+// would send machines, and the next tier, what the later merge replaced. asked is zero when the
+// build's request time is not known, and such an outcome is taken as before.
+func planBuilt(ctx context.Context, open *stores, module, commit, failed string, asked time.Time) {
 	inv := open.inventory
 	plans, err := inv.OpenPlans(ctx)
 	if err != nil {
@@ -315,6 +321,9 @@ func planBuilt(ctx context.Context, open *stores, module, commit, failed string)
 			state = &inventory.PlanModule{}
 			p.Modules[module] = state
 		}
+		if askedBefore(asked, state.AskedAt) {
+			continue
+		}
 		if failed != "" {
 			state.State = "failed"
 			state.Why = failed
@@ -549,7 +558,8 @@ func planFailedBuild(ctx context.Context, open *stores, result link.BuildResult)
 	}
 	for _, e := range entries {
 		if repositoryMatches(e.Source.Repository, result.Repository) && e.Source.Path == result.Path {
-			planBuilt(ctx, open, e.Manifest.Module, result.Commit, result.Failed)
+			asked, _ := link.BuildAskedAt(result.ID)
+			planBuilt(ctx, open, e.Manifest.Module, result.Commit, result.Failed, asked)
 			return
 		}
 	}
@@ -791,6 +801,11 @@ func settleFromRecords(p *inventory.Plan, tier []string, recorded map[string][]i
 			if b.At.Before(*s.AskedAt) {
 				break
 			}
+			// Recorded after the ask and asked before it: an earlier ask's late outcome, not this
+			// one's (novox/hq 04-ISSUES/219).
+			if askedBefore(b.Asked, s.AskedAt) {
+				continue
+			}
 			outcome = &b
 		}
 		if outcome == nil {
@@ -812,3 +827,9 @@ func settleFromRecords(p *inventory.Plan, tier []string, recorded map[string][]i
 	}
 	return changed
 }
+
+// askedBefore is whether a build asked at asked was asked before a plan asked for its module — and
+// so is not that plan's outcome (novox/hq 04-ISSUES/219). False when either time is not known.
+func askedBefore(asked time.Time, planAsked *time.Time) bool {
+	return !asked.IsZero() && planAsked != nil && asked.Before(*planAsked)
+}

cmd/mesh-controller/release_plan_test.go

@@ -155,6 +155,24 @@ func TestAPlanSettlesAnAskedBuildFromTheRecords(t *testing.T) {
 		t.Errorf("an ask with no record after it was settled: %+v", s)
 	}
 
+	// novox/hq 04-ISSUES/219: a build recorded after the ask but asked before it — an earlier
+	// plan's late outcome — is not this ask's, built or failed.
+	r := inventory.Plan{ID: "plan-3", Tiers: [][]string{{"postgres"}},
+		Modules: map[string]*inventory.PlanModule{"postgres": {State: "asked", AskedAt: &asked}}}
+	late := map[string][]inventory.Build{"postgres": {
+		{ID: "build-old", Commit: "efff5415", Asked: asked.Add(-18 * time.Minute), At: asked.Add(12 * time.Minute)},
+	}}
+	if settleFromRecords(&r, r.Tiers[0], late) || r.Modules["postgres"].State != "asked" {
+		t.Errorf("an earlier ask's late outcome settled this ask: %+v", r.Modules["postgres"])
+	}
+	// Newest heard first: the earlier ask's late outcome, then this ask's own, heard before it.
+	late["postgres"] = append(late["postgres"], inventory.Build{ID: "build-mine", Commit: "4bcd5f73",
+		Asked: asked.Add(time.Second), At: asked.Add(5 * time.Minute)})
+	if !settleFromRecords(&r, r.Tiers[0], late) || r.Modules["postgres"].State != "built" ||
+		r.Modules["postgres"].Commit != "4bcd5f73" {
+		t.Errorf("this ask's own outcome, heard before the earlier ask's, did not settle it: %+v", r.Modules["postgres"])
+	}
+
 	// A failure recorded after the ask fails the plan, as hearing it would have.
 	q := inventory.Plan{ID: "plan-2", Tiers: [][]string{{"x"}},
 		Modules: map[string]*inventory.PlanModule{"x": {State: "asked", AskedAt: &asked}}}