Enzyme returning zero derivative

[swilliamson7]

I am not sure if this is me setting up the problem wrong or what, but I'm getting a zero derivative when I shouldn't be. The script to run is here: https://github.com/swilliamson7/data_assimilation_2/blob/main/barotropic_gyre/zero_derivative_error.jl, it's mainly just ShallowWaters.jl code. At the end I check dS.constants.cD, which should be the derivative with respect to a coefficient that appears in the model equations, and see that this is zero. However, it directly is used to compute the output of my integration S.Prog.u[25, 25] (this is just a random entry in the field, the actual choice shouldn't matter), so I really don't think the derivative should be appearing as zero. Any help/advice would be much appreciated!

[swilliamson7]

Whoops, found my mistake! Closing now