add placeholders for assigning collection types

lib/spack/spack/repo.py

@@ -1374,6 +1374,12 @@ def get_pkg_class(self, pkg_name):
         # sets attributes that it used to)
         new_overidden_attrs = {}
         for key, val in new_cfg_settings.items():
+            if hasattr(cls, key):
+                new_overidden_attrs[key] = getattr(cls, key)
+            if isinstance(val, list):
+                raise spack.config.ConfigError("Unsupported attribute value: list")
+            elif isinstance(val, dict):
+                raise spack.config.ConfigError("Unsupported attribute value: dict")
             if key not in ["git", "url", "submodules"]:
                 # Infer type
                 val = yaml.load(val)

lib/spack/spack/schema/packages.py

@@ -99,8 +99,15 @@
                             },
                         },
                         "patternProperties": {
-                            r"\w[\w-]*": {
-                                "type": "string",
+                            r"\w+": {
+                                "oneOf": [
+                                    {"type": "string"},
+                                    {"type": "array", "items": {"type": "string"}},
+                                    {
+                                        "type": "object",
+                                        "patternProperties": {r"\w+": {"type": "string"}},
+                                    },
+                                ]
                             },
                         },
                     },

lib/spack/spack/test/concretize_preferences.py

@@ -179,7 +179,7 @@ def test_preferred_providers(self):
         spec = concretize("mpileaks")
         assert "zmpi" in spec
 
-    def test_config_set_url_for_package(self, mutable_mock_repo):
+    def test_config_set_pkg_property_url(self, mutable_mock_repo):
         """Test preferred providers of virtual packages are
         applied correctly
         """
@@ -195,10 +195,8 @@ def test_config_set_url_for_package(self, mutable_mock_repo):
         spec = concretize("mpileaks")
         assert spec.package.fetcher[0].url == "http://www.llnl.gov/mpileaks-2.3.tar.gz"
 
-    def test_config_set_package_property(self, mutable_mock_repo):
-        """Test preferred providers of virtual packages are
-        applied correctly
-        """
+    def test_config_set_pkg_property_new(self, mutable_mock_repo):
+        """Test that you can set arbitrary attributes on the Package class"""
         update_packages(
             "mpileaks",
             "package_attributes",
@@ -208,6 +206,12 @@ def test_config_set_package_property(self, mutable_mock_repo):
         assert spec.package.x == 1
         assert spec.package.y == True
 
+    def test_config_set_pkg_property_collecton_unsupported(self, mutable_mock_repo):
+        """Test that an error is raised if you attempt to assign a list value"""
+        update_packages("mpileaks", "package_attributes", {"x": ["a", "b"]})
+        with pytest.raises(ConfigError):
+            spec = concretize("mpileaks")
+
     def test_preferred(self):
         """ "Test packages with some version marked as preferred=True"""
         spec = Spec("python")