mesh-build-image: let the module's own guard decide whether the real-buildah tests run, so a check sandbox where rootless buildah cannot unshare skips them loudly instead of failing every catalogue check (issue 1894)

modules/mesh-build-image/cmd/mesh-build-image/integration_test.go

@@ -53,6 +53,11 @@ func realModule(t *testing.T) (*Module, *keptStates) {
 	m := &Module{Node: "ace", Account: u.Username, UID: u.Uid, Home: home, Work: t.TempDir(), Store: t.TempDir(),
 		Steps: states.putStep, Ctx: context.Background(), Say: t.Logf, Run: StepRunner(home),
 		FetchOptions: []buildstep.Option{buildstep.AllowFileRemote()}}
+	// buildah being installed is not enough: inside the check's sandbox rootless buildah cannot make its user
+	// namespace, so the module's own guard decides, as it does before every step (issue 1894).
+	if err := m.Check(context.Background()); err != nil {
+		t.Skipf("NOT RUN: this machine cannot build images where the check runs (%v); proven live on a build node", err)
+	}
 	return m, states
 }