The gate's module check notes a seat another module declares, which it was not given (hq issue 364)

The gate passes only the manifests a change touches, so a module that starts using the operator channel
was refused for a declaration it could not see. Over every manifest it stays a refusal.

internal/builder/check.go

@@ -543,6 +543,11 @@ func passedSoFar(ran []string) string {
 	return strings.Join(ran, ", ") + " passed; "
 }
 
+// SomeManifestsEnv tells the judge's module check that the manifests it is given are only those a change touches,
+// so a seat another module of the repository declares is a note there, not a refusal (novox/hq issue 364). A judge
+// that predates it reads nothing of it and refuses as before.
+const SomeManifestsEnv = "MESH_MODULE_CHECK_SOME=1"
+
 // gateLayer runs the gate: the touched manifests through `module check`, every machine composed with the
 // change, and the replays of what the mesh runs. It answers the gate's verdict and summary.
 func gateLayer(ctx context.Context, spec CheckSpec, tree, root, gate, verdictFile string, env []string,
@@ -562,7 +567,7 @@ func gateLayer(ctx context.Context, spec CheckSpec, tree, root, gate, verdictFil
 		checked := func(dir string) (string, error) {
 			var own tail
 			cmd := exec.CommandContext(ctx, "docker", LabelledArgs("docker",
-				inToolchain(dir, env, append([]string{gate, "module", "check"}, manifests...)...), spec.ID)...)
+				inToolchain(dir, append(append([]string{}, env...), SomeManifestsEnv), append([]string{gate, "module", "check"}, manifests...)...), spec.ID)...)
 			inItsOwnGroup(cmd)
 			w := io.MultiWriter(out, &own)
 			cmd.Stdout, cmd.Stderr = w, w

internal/catalogue/seats_declared.go

@@ -230,6 +230,14 @@ type Shelf map[string]Manifest
 //
 // Run at registration, which is the last moment the mesh can still refuse: after it, a caller is
 // bound to a seat and a refusal is an outage rather than a conversation.
+// UndeclaredSeat ends the problem of a `uses` or a claim naming a seat no manifest given declares: over the whole
+// catalogue (registration, the catalogue's own check) a refusal, and over some manifests alone a seat whose
+// declaring module was not given (novox/hq issue 364).
+const UndeclaredSeat = "which no module declares and the mesh does not define"
+
+// IsUndeclaredSeat says whether a problem CatalogueProblems gave is a seat no manifest given declares.
+func IsUndeclaredSeat(problem string) bool { return strings.HasSuffix(problem, UndeclaredSeat) }
+
 func CatalogueProblems(shelf Shelf) []string {
 	var problems []string
 
@@ -282,7 +290,7 @@ func CatalogueProblems(shelf Shelf) []string {
 		for _, u := range m.Uses {
 			if !exists(u) {
 				problems = append(problems, fmt.Sprintf(
-					"%s uses the seat %q, which no module declares and the mesh does not define",
+					"%s uses the seat %q, "+UndeclaredSeat,
 					module, u))
 			}
 		}
@@ -290,7 +298,7 @@ func CatalogueProblems(shelf Shelf) []string {
 		for _, c := range m.Claims {
 			if !exists(c.Name) {
 				problems = append(problems, fmt.Sprintf(
-					"%s claims the seat %q, which no module declares and the mesh does not define",
+					"%s claims the seat %q, "+UndeclaredSeat,
 					module, c.Name))
 				continue
 			}