Thanks for the bug report with reproducing example. I have a fix in https://gitlab.com/petsc/petsc/-/merge_requests/5797
Barry > On Nov 2, 2022, at 6:52 AM, Stephan Köhler > <stephan.koeh...@math.tu-freiberg.de> wrote: > > Dear PETSc/Tao team, > > it seems to be that there is a bug in the LMVM matrix class: > > In the function MatCreateVecs_LMVM, see, e.g., > https://petsc.org/release/src/ksp/ksp/utils/lmvm/lmvmimpl.c.html at line 214. > it is not checked if the vectors *L, or *R are NULL. This is, in > particular, a problem if this matrix class is combined with the Schur > complement matrix class, since MatMult_SchurComplement > calls this function with NULL as *R, see, e.g. > https://petsc.org/release/src/ksp/ksp/utils/schurm/schurm.c.html at line 66. > > I attach a minimal example. You need to modify the paths to the PETSc > installation in the makefile. > > Best regards > Stephan Köhler > > -- > Stephan Köhler > TU Bergakademie Freiberg > Institut für numerische Mathematik und Optimierung > > Akademiestraße 6 > 09599 Freiberg > Gebäudeteil Mittelbau, Zimmer 2.07 > > Telefon: +49 (0)3731 39-3173 (Büro) > > <Minimal_example_schur_lmvm.tar.gz><OpenPGP_0xC9BF2C20DFE9F713.asc>
