L-Shaped Number of Processes for mpiexec

[LennonConson]

I noticed that run_all.py uses only 2 processes for farmer_lshapedhub.py when there is 3 scenarios with 2 cylinders. I think there are 6 ranks, but when I run:
mpiexec -np 6 python -u -m mpi4py farmer_lshapedhub.py --num-scens 3 --bundles-per-rank=0 --max-iterations=50 --solver-name=gurobi_persistent --rel-gap=0.0 --xhatlshaped
I get

  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/home/lennon/.local/lib/python3.13/site-packages/mpi4py/__main__.py", line 7, in <module>
    main()
    ~~~~^^
  File "/home/lennon/.local/lib/python3.13/site-packages/mpi4py/run.py", line 214, in main
    run_command_line(args)
    ~~~~~~~~~~~~~~~~^^^^^^
  File "/home/lennon/.local/lib/python3.13/site-packages/mpi4py/run.py", line 46, in run_command_line
    run_path(sys.argv[0], run_name='__main__')
    ~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen runpy>", line 287, in run_path
  File "<frozen runpy>", line 98, in _run_module_code
  File "<frozen runpy>", line 88, in _run_code
  File "farmer_lshapedhub.py", line 113, in <module>
    main()
    ~~~~^^
  File "farmer_lshapedhub.py", line 109, in main
    WheelSpinner(hub_dict, list_of_spoke_dict).spin()
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/home/lennon/git/tl-saa/external/mpi-sppy/mpisppy/spin_the_wheel.py", line 41, in spin
    return self.run(comm_world=comm_world)
           ~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/lennon/git/tl-saa/external/mpi-sppy/mpisppy/spin_the_wheel.py", line 137, in run
    spcomm.main()
    ~~~~~~~~~~~^^
  File "/home/lennon/git/tl-saa/external/mpi-sppy/mpisppy/cylinders/hub.py", line 388, in main
    self.opt.lshaped_algorithm()
    ~~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/home/lennon/git/tl-saa/external/mpi-sppy/mpisppy/opt/lshaped.py", line 647, in lshaped_algorithm
    cuts_added = m.bender.generate_cut()
  File "/home/lennon/.local/lib/python3.13/site-packages/pyomo/contrib/benders/benders_cuts.py", line 379, in generate_cut
    root_eta = self.all_root_etas[global_subproblem_ndx]
               ~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^
IndexError: list index out of range

Abort(1) on node 2 (rank 2 in comm 0): application called MPI_Abort(MPI_COMM_WORLD, 1) - process 2
Abort(1) on node 4 (rank 4 in comm 0): application called MPI_Abort(MPI_COMM_WORLD, 1) - process 4

I am a doing something wrong or is this a bug?

[DLWoodruff]

This seems to be a bug. Note that it fails in a different way with four processors. L-shaped does not get a lot of use, but we will try to get this fixed in the next few weeks.