Merge pull request 'The gate's module check notes a seat another module declares, which it was not given (hq issue 364)' (#195) from fix/364-a-touched-manifest-uses-a-seat-another-module-declares into main

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