A need is kept once per provision, consumer, local name and provider

Two consumers of one same-node provision produced two raw needs and, fanned out per
consumer, four — the same credential twice for each. Harmless, since a pair is one
row however often it is asked for, and wrong all the same.

internal/catalogue/resolve.go

@@ -834,6 +834,19 @@ func providersFirst(order []string, shelf map[string]Manifest) []string {
 // losing the one it depends on.
 func perConsumer(needs []Needed, order []string, catalogue map[string]Manifest) []Needed {
 	out := make([]Needed, 0, len(needs))
+	// Once per (provision, consumer, local name, provider). The walk over names visits a
+	// same-node provision once per module that mentions it, so two consumers of one produced two
+	// raw needs and, fanned out below, four — the same credential twice for each. Harmless
+	// downstream, since a pair is one row however often it is asked for, and wrong all the same.
+	seen := map[[4]string]bool{}
+	keep := func(n Needed) {
+		key := [4]string{n.Name, n.For, n.Local, n.From}
+		if seen[key] {
+			return
+		}
+		seen[key] = true
+		out = append(out, n)
+	}
 	for _, n := range needs {
 		var wanted bool
 		for _, name := range order {
@@ -849,13 +862,15 @@ func perConsumer(needs []Needed, order []string, catalogue map[string]Manifest)
 				copied.For = m.Module
 				// And once per file THIS module keeps the credential in, where it keeps several
 				// (ADR 0094) — here, where the consumer is finally known, not on the walk above.
-				out = eachLocal(out, catalogue, copied)
+				for _, one := range eachLocal(nil, catalogue, copied) {
+					keep(one)
+				}
 				wanted = true
 				break
 			}
 		}
 		if !wanted {
-			out = append(out, n)
+			keep(n)
 		}
 	}
 	return out