PackageBase: make _update_external_dependencies private (#50580)

lib/spack/spack/package_base.py

@@ -986,7 +986,9 @@ def url_for_version(self, version):
         """
         return self._implement_all_urls_for_version(version)[0]
 
-    def update_external_dependencies(self, extendee_spec=None):
+    def _update_external_dependencies(
+        self, extendee_spec: Optional[spack.spec.Spec] = None
+    ) -> None:
         """
         Method to override in package classes to handle external dependencies
         """

lib/spack/spack/solver/asp.py

@@ -3894,7 +3894,7 @@ def external_spec_selected(self, node, idx):
 
         if extendee_spec:
             extendee_node = SpecBuilder.make_node(pkg=extendee_spec.name)
-            package.update_external_dependencies(self._specs.get(extendee_node, None))
+            package._update_external_dependencies(self._specs.get(extendee_node))
 
     def depends_on(self, parent_node, dependency_node, type):
         dependency_spec = self._specs[dependency_node]