core changes to allow setting git/url attribute on packages

lib/spack/spack/repo.py

@@ -1362,6 +1362,11 @@ def get_pkg_class(self, pkg_name):
         if not inspect.isclass(cls):
             tty.die("%s.%s is not a class" % (pkg_name, class_name))
 
+        # packages.yaml config can override package attributes
+        settings = spack.config.get("packages").get(pkg_name, {}).get("set", {})
+        for key, val in settings.items():
+            setattr(cls, key, val)
+
         return cls
 
     def __str__(self):

lib/spack/spack/schema/packages.py

@@ -82,6 +82,23 @@
                             },
                         },
                     },
+                    # If 'get_full_repo' is promoted to a Package-level
+                    # attribute, it could be useful to set it here
+                    "set": {
+                        "type": "object",
+                        "additionalProperties": False,
+                        "properties": {
+                            "git": {
+                                "type": "string",
+                            },
+                            "url": {
+                                "type": "string",
+                            },
+                            "submodules": {
+                                "type": "boolean",
+                            },
+                        },
+                    },
                     "providers": {
                         "type": "object",
                         "default": {},