patch cache: fix bug finding inherited packages (#29574)

lib/spack/spack/package.py

@@ -400,6 +400,21 @@ def fullname(self):
         """Name of this package, including the namespace"""
         return '%s.%s' % (self.namespace, self.name)
 
+    @property
+    def fullnames(self):
+        """
+        Fullnames for this package and any packages from which it inherits.
+        """
+        fullnames = []
+        for cls in inspect.getmro(self):
+            namespace = getattr(cls, 'namespace', None)
+            if namespace:
+                fullnames.append('%s.%s' % (namespace, self.name))
+            if namespace == 'builtin':
+                # builtin packages cannot inherit from other repos
+                break
+        return fullnames
+
     @property
     def name(self):
         """The name of this package.
@@ -911,6 +926,10 @@ def fullname(self):
         """Name of this package, including namespace: namespace.name."""
         return type(self).fullname
 
+    @property
+    def fullnames(self):
+        return type(self).fullnames
+
     @property
     def name(self):
         """Name of this package (the module without parent modules)."""

lib/spack/spack/patch.py

@@ -368,8 +368,12 @@ def patch_for_package(self, sha256, pkg):
                 "Couldn't find patch for package %s with sha256: %s"
                 % (pkg.fullname, sha256))
 
-        patch_dict = sha_index.get(pkg.fullname)
-        if not patch_dict:
+        # Find patches for this class or any class it inherits from
+        for fullname in pkg.fullnames:
+            patch_dict = sha_index.get(fullname)
+            if patch_dict:
+                break
+        else:
             raise NoSuchPatchError(
                 "Couldn't find patch for package %s with sha256: %s"
                 % (pkg.fullname, sha256))