FMPy-0.3.29 regression compared to FMPy-0.3.21

[adrpo]

Newer versions of FMPy fail to simulate FMU.

(lpy) adrpo33@win06527:~/testing/fmi$ pip install FMPy
(lpy) adrpo33@win06527:~/testing/fmi$ python3 -m fmpy --version
FMPy version 0.3.29
// simulate with FMPy
python3 -m fmpy simulate  --output-file Buildings_latest_Buildings.DHC.Plants.Combined.Controls.BaseClasses.Validation.StagingPlant_res.csv --start-time 0 --stop-time 30000 --timeout 800 --relative-tolerance 1e-06 --interface-type ModelExchange --solver CVode --output-interval 12 Buildings_latest_Buildings_DHC_Plants_Combined_Controls_BaseClasses_Validation_StagingPlant.fmu
[ERROR][rank 0][/home/runner/work/FMPy/FMPy/native/sundials-7.5.0/src/cvode/cvode.c:3739][cvHandleFailure] At t = 1057.17731931344 and h = 0.0006, the error test failed repeatedly or with |h| = hmin.
Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/home/adrpo33/lpy/lib/python3.12/site-packages/fmpy/__main__.py", line 4, in <module>
    main()
  File "/home/adrpo33/lpy/lib/python3.12/site-packages/fmpy/cli.py", line 186, in main
    result = simulate_fmu(args.fmu_filename,
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/adrpo33/lpy/lib/python3.12/site-packages/fmpy/simulation.py", line 788, in simulate_fmu
    result = simulateME(model_description, fmu, start_time, stop_time, solver, step_size, relative_tolerance, start_values, apply_default_start_values, input, output, output_interval, record_events, timeout, step_finished, validate, set_stop_time)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/adrpo33/lpy/lib/python3.12/site-packages/fmpy/simulation.py", line 1101, in simulateME
    state_event, roots_found, time = solver.step(time, next_communication_point)
                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/adrpo33/lpy/lib/python3.12/site-packages/fmpy/sundials/__init__.py", line 185, in step
    raise RuntimeError("CVode error (code %s) in module %s, function %s: %s" % self.error_info)
RuntimeError: CVode error (code -3) in module cvHandleFailure, function /home/runner/work/FMPy/FMPy/native/sundials-7.5.0/src/cvode/cvode.c: At t = 1057.17731931344 and h = 0.0006, the error test failed repeatedly or with |h| = hmin.

Install a older version:
(lpy) adrpo33@win06527:~/testing/fmi$ pip install FMPy==0.3.21
(lpy) adrpo33@win06527:~/testing/fmi$ python3 -m fmpy --version
FMPy version 0.3.21

Works fine:
(lpy) adrpo33@win06527:~/testing/fmi$ python3 -m fmpy simulate  --output-file Buildings_latest_Buildings.DHC.Plants.Combined.Controls.BaseClasses.Validation.StagingPlant_res.csv --start-time 0 --stop-time 30000 --timeout 800 --relative-tolerance 1e-06 --interface-type ModelExchange --solver CVode --output-interval 12 Buildings_latest_Buildings_DHC_Plants_Combined_Controls_BaseClasses_Validation_StagingPlant.fmu

You can generate the FMU with OpenModelica via:

// b.mos script
loadModel(Buildings); getErrorString();
buildModelFMU(Buildings.DHC.Plants.Combined.Controls.BaseClasses.Validation.StagingPlant,fileNamePrefix="Buildings_latest_Buildings_DHC_Plants_Combined_Controls_BaseClasses_Validation_StagingPlant",fmuType="me",version="2.0",platforms={"static"}); getErrorString();

// generate the FMU
omc b.mos

But is also uloaded here (Linux version).
Buildings_latest_Buildings_DHC_Plants_Combined_Controls_BaseClasses_Validation_StagingPlant.zip

[casella]

For the record, the regression was found by the OpenModelica CI testing, see report.