internal/catalogue/build.go

@@ -142,7 +142,14 @@ func (b *Build) problems(module string) []string {
 		// is which compiler — because the mesh chooses that, and cannot choose for a module that
 		// has not said.
 		if a.Kind == ArtifactBundle || a.Kind == ArtifactPackage {
-			if a.From != "" {
+			// **Except for a language that compiles to a binary, where it names which one**
+			// (novox/hq 04-ISSUES/142). A bundle in an interpreted language is the module's own
+			// directory compiled whole, and naming a source would be describing its own build. A
+			// repository written in a compiled language holds several commands — the host and its
+			// bootstrap live in one, and the mesh needs the host — and "the module's own directory"
+			// is then not a package at all. So the compiled case may say which package, and says
+			// the module root by saying nothing.
+			if a.From != "" && !compilesToABinary(a.Language) {
 				problems = append(problems, fmt.Sprintf(
 					"%s: %q is a bundle and names what it is built from (%q). A bundle is built "+
 						"from the module's own directory; what it says is the language",

internal/catalogue/go_bundle_test.go

@@ -0,0 +1,37 @@
+package catalogue
+
+import "testing"
+
+// A bundle is the module's own directory compiled whole, and naming a source would be describing its
+// own build. That holds for an interpreted language and cannot hold for a compiled one: a repository
+// written in Go carries several commands — the host and its bootstrap live in one — and "the module's
+// own directory" is then not a package at all (novox/hq 04-ISSUES/142).
+
+func TestAGoBundleMayNameItsCommand(t *testing.T) {
+	b := &Build{Artifacts: []Artifact{{
+		Name: "host-arch", Kind: ArtifactBundle, Language: "go", System: "arch",
+		From: "cmd/mesh-host",
+	}}}
+	if p := b.problems("mesh-host"); len(p) != 0 {
+		t.Fatalf("a go bundle naming its command was refused: %v", p)
+	}
+}
+
+func TestAnInterpretedBundleStillMayNotNameASource(t *testing.T) {
+	b := &Build{Artifacts: []Artifact{{
+		Name: "tools", Kind: ArtifactBundle, Language: "typescript", From: "src",
+	}}}
+	p := b.problems("something")
+	if len(p) == 0 {
+		t.Fatal("an interpreted bundle naming what it is built from was accepted")
+	}
+}
+
+func TestACompiledBundleStillMustSayItsSystem(t *testing.T) {
+	b := &Build{Artifacts: []Artifact{{
+		Name: "host", Kind: ArtifactBundle, Language: "go", From: "cmd/mesh-host",
+	}}}
+	if len(b.problems("mesh-host")) == 0 {
+		t.Fatal("a compiled bundle with no system was accepted")
+	}
+}