This line: https://github.com/CVMix/CVMix-src/blob/52aac958e05cdb2471dc73f9ef7fb4e816c550f2/src/shared/cvmix_convection.F90#L227 uses an optional argument, and produces a run-time error when compiled in debug if that optional argument is not provided. I think the intention was ``` 227 CVmix_conv_params_in) ``` Similarly, this https://github.com/CVMix/CVMix-src/blob/52aac958e05cdb2471dc73f9ef7fb4e816c550f2/src/shared/cvmix_convection.F90#L404 should be ``` 404 CVmix_conv_params_out) ```