Name the build errors in one place, and which are not built again until the source changes (issue 1587, S14, ADR 0498 §2 §4 §5)

not stored, not pinned, version taken and refused kind (moved here from the builder);
FailedUntilChanged keeps an unpinned upstream or a taken version from rebuilding in a
loop, while a failed push is built again.

go/delivery/builder.go

@@ -135,6 +135,26 @@ func (b BuilderBuild) Referenced() (ok bool, missing []string) {
 	return b.State == BuildDone && len(b.Artifacts) > 0 && len(missing) == 0, missing
 }
 
+// The prefixes of a failed key's error that a build module answers (novox/hq ADR 0498 clauses 2, 4 and 5; ADR 0478
+// clause 2), each followed by the artifact and the words of what refused it.
+const (
+	// NotStored: the push of a bundle, an archive or an upstream copy to the artifact store failed; built again.
+	NotStored = "not stored: "
+	// NotPinned: an upstream artifact names no digest.
+	NotPinned = "not pinned: "
+	// VersionTaken: the package registry holds the package's version with another packed file.
+	VersionTaken = "version taken: "
+	// RefusedKind: no build module builds this kind of artifact in its language.
+	RefusedKind = "refused kind: "
+)
+
+// FailedUntilChanged says whether a failed key's error is one that is not built again until the module's fingerprint
+// changes (not pinned, version taken, refused kind: the same source fails the same way); every other failed key, a
+// push that was not stored included, is built again as a new revision (ADR 0429 clause 18).
+func FailedUntilChanged(err string) bool {
+	return strings.HasPrefix(err, NotPinned) || strings.HasPrefix(err, VersionTaken) || strings.HasPrefix(err, RefusedKind)
+}
+
 // ToolchainUsed is what a build used for one language (ADR 0405 clauses 2 and 7): the installed toolchain's version and
 // the build module's recipe version.
 type ToolchainUsed struct {

go/delivery/builder_reference_test.go

@@ -74,3 +74,25 @@ func TestReferencedNamesTheArtifactsWithoutAReference(t *testing.T) {
 	}
 }
 
+// The errors a build module answers open with a fixed prefix (ADR 0498 clauses 2, 4 and 5; ADR 0478 clause 2), and three
+// of them are not built again until the module's fingerprint changes; a failed push is.
+func TestOnlyAPushFailureIsBuiltAgainBeforeTheFingerprintChanges(t *testing.T) {
+	for _, c := range []struct {
+		err   string
+		again bool
+	}{
+		{NotStored + "code: the store said 500", true},
+		{NotPinned + "nats: upstream names no digest", false},
+		{VersionTaken + "@novox/mesh-sdk@0.1.15 holds another file", false},
+		{RefusedKind + "a package in go", false},
+		{"go test: 2 failed", true},
+	} {
+		if got := FailedUntilChanged(c.err); got == c.again {
+			t.Errorf("FailedUntilChanged(%q) = %v", c.err, got)
+		}
+	}
+	if NotStored != "not stored: " || NotPinned != "not pinned: " || VersionTaken != "version taken: " || RefusedKind != "refused kind: " {
+		t.Fatal("a prefix changed its words")
+	}
+}
+