Running a machine in NixOS tests

I want to run tests on my machines using runNixOSTest. The interface demands a configuration to be declared within the module, but what I’d want is to reference self.nixosConfigurations.something from the same flake, rather than writing a new, less accurate, representation of the configuration I’d actually run. If I try to do so, I get infinite recursion errors (the configs refer to self, so does runNixOSTest). Has anybody found a way out of this?

let-bind the machine configuration and assign it to both nixosConfigurations.something and into runNixOSTest?