PetscDS is part of DM, so you have to "use petscdm". The example src/dm/impls/plex/tutorials/ex4f90.F90 uses PetscDS. The configure option --with-fortran-interfaces=1 is deprecated, it is no longer needed. Jose
> El 26 nov 2025, a las 9:31, Berends, C.J. (Tijn) via petsc-users > <[email protected]> escribió: > > Dear petsc folks, > > I am trying to set up a very basic example program in Fortran, using Petsc to > solve a simple Poisson problem (d2u/dx2 = f). > > However, I am running into problems when I try to call PetscDSSetResidual to > set the function pointers for the residual. According to the documentation, > this function is part of the petcds module, but while the header file > (petscds.h) exists in my Petsc include directotry, the Fortran module > (petscds.mod) does not. Therefore, my code won't compile. > > I have currently got Petsc installed via Homebrew. I have tried cloning the > Petsc git repository and building that, using the configuration option > --with-fortran-interfaces=1, but still the petscds.mod file is not there. > > Am I doing something wrong, or can it be that this particular Fortran > interface is just missing? > > If you need any additional information from me, please let me know. > > Kind regards, > Tijn Berends > > > > dr. C. J. (Tijn) Berends > Post-doc (palaeo)glaciology > Institute for Marine and Atmospheric research Utrecht (IMAU), Utrecht > University, The Netherlands > Buys Ballot Building (BBG), Room 6.67
