The sandbox refuses no module the node holds composing without the change, a module blamed for a refusal among them (issue 774, review round 1)

internal/compose/input.go

@@ -249,6 +249,9 @@ type ComposedHow struct {
 	Held map[string]string
 	// Running is what runs of each held module, its own composition, by which it is carried as it runs.
 	Running []delivery.Composed
+	// HeldBefore is each module the node holds composing without the change (the candidate's base), held by the read or
+	// blamed later for a refusal: the change refuses none of them (issue 774, review round 1).
+	HeldBefore map[string]string
 }
 
 // Place is where a node is, as its placement says (inv.Overlay).