separate custom openapi test from the others

Makefile

@@ -229,7 +229,8 @@ generate-kustomize-api: $(MYGOBIN)/k8scopy
 
 .PHONY: test-unit-kustomize-api
 test-unit-kustomize-api: build-kustomize-api
-	cd api; go test ./...  -ldflags "-X sigs.k8s.io/kustomize/api/provenance.version=v444.333.222"
+	cd api; go test ./...  -ldflags "-X sigs.k8s.io/kustomize/api/provenance.version=v444.333.222"; \
+	cd krusty; OPENAPI_TEST=true go test -run TestCustomOpenAPIFieldFromComponentWithOverlays
 
 .PHONY: test-unit-kustomize-plugins
 test-unit-kustomize-plugins:

api/krusty/openapicustomschema_test.go

@@ -5,6 +5,7 @@ package krusty_test
 
 import (
 	"io/ioutil"
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -350,6 +351,10 @@ func TestCustomOpenAPIFieldFromComponent(t *testing.T) {
 // test for https://github.com/kubernetes-sigs/kustomize/issues/4179
 // kustomize is not seeing the openapi field from the component defined in the overlay
 func TestCustomOpenAPIFieldFromComponentWithOverlays(t *testing.T) {
+	if val, ok := os.LookupEnv("OPENAPI_TEST"); !ok || val != "true" {
+		t.SkipNow()
+	}
+
 	th := kusttest_test.MakeHarness(t)
 
 	// overlay declaring the component