crdgen: compare metav1 pkg by ID

This patch updates the way the CRD generator compares an imported
metav1 package. Previously the comparison occurred using a Golang
equality operator, !=, against two, in-memory data structures.
However, this fails when multiple root paths are loaded. Their
metav1 packages are identical, just not identical objects in
memory. This patch updates the comparison to compare the package
IDs, not the instance of the object.

pkg/crd/gen.go

@@ -247,7 +247,12 @@ func FindKubeKinds(parser *Parser, metav1Pkg *loader.Package) map[schema.GroupKi
 			}
 			fieldPkgPath := loader.NonVendorPath(namedField.Obj().Pkg().Path())
 			fieldPkg := pkg.Imports()[fieldPkgPath]
-			if fieldPkg != metav1Pkg {
+
+			// Compare the metav1 package by ID and not by the actual instance
+			// of the object. The objects in memory could be different due to
+			// loading from different root paths, even when they both refer to
+			// the same metav1 package.
+			if fieldPkg == nil || fieldPkg.ID != metav1Pkg.ID {
 				continue
 			}