Dear all, This is a bit of a silly comment, but I have noticed that since the upgrade to python3 I can’t terminate a simulation with ctrl+c. I get the following on the screen and the simulation continues to run: ^CTraceback (most recent call last): File "libpetsc4py/libpetsc4py.pyx", line 858, in libpetsc4py.MatMult_Python File "/Users/dkc16gyu/firedrake/src/PyOP2/pyop2/petsc_base.py", line 1008, in mult x.comm.tompi4py().bcast(a) File "PETSc/Comm.pyx", line 105, in petsc4py.PETSc.Comm.tompi4py File "PETSc/petscmpi.pxi", line 50, in petsc4py.PETSc.mpi4py_Comm_New File "<frozen importlib._bootstrap>", line 961, in _find_and_load File "<frozen importlib._bootstrap>", line 946, in _find_and_load_unlocked File "<frozen importlib._bootstrap>", line 885, in _find_spec File "<frozen importlib._bootstrap_external>", line 1157, in find_spec File "<frozen importlib._bootstrap_external>", line 1129, in _get_spec File "<frozen importlib._bootstrap_external>", line 1268, in find_spec File "<frozen importlib._bootstrap_external>", line 59, in _path_join KeyboardInterrupt The above exception was the direct cause of the following exception: SystemError: <built-in method insert of list object at 0x108236708> returned a result with an error set Exception ignored in: 'petsc4py.PETSc.traceback' SystemError: <built-in method insert of list object at 0x108236708> returned a result with an error set Best wishes, Anna.