Describe the bug

For context, moduleType and extendModules duplicate the configuration namespace, but with user-defined modules added.

Extending the configuration more than once makes name throw a duplicate definition error.

Steps To Reproduce

Suppose we have

{ config, moduleType, ... }: {
  options.variants = mkOption { type = attrsOf moduleType; };
  options.result = mkOption { type = str; };
}

then

variants.foo = { name, ... }: { result = name; }

will result in

variants.foo.result == "foo"

but

variants.foo.variants.bar = { name, ... }: { result = name; }

causes an error because name is redefined in the second level.

Expected behavior

• name does not throw an error.

• All names can be used.

Additional context

Discovered in #176557 matrix module.

This can be solved by defining name in specialArgs, or by making the parameter name configurable (creating PR in a minute).

Notify maintainers

@infinisil