[firedrake] Questions about Flooddrake

Hello all, I am a beginner for Firedrake whose application is simulation of shallow water equation. When I was running several example codes of Flooddrake, I encountered the error: firedrake:WARNING Your kernel body contains a double indirection. You should update it to single indirections. and the compilation process cannot be performed. Is this error due to the incompatibility between Firedrake and Flooddrake? Because it seems that Flooddrake is not maintained for a long time. Is Thetis the new alternative to Flooddrake now? Thank you in advance for answering my questions. Boyuan