Flatcal tries to create an empty spectral cube

[ld-cd]

LaserCal FlatCal creates an empty spectral cube when the specified duration is less than the flatcal chunk time (LaserCalibrator().cfg.flatcal.chunk_time ???)

[ld-cd]

could not broadcast input array from shape (0,140,146) into shape (6,140,146)
  File "/home/cudaa/Workspace/software/MKIDPipeline/mkidpipeline/steps/flatcal.py", line 363, in make_spectral_cube
    cps_cube_list[:, :, :, w_idx] = hdul['SCIENCE'].data
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^
  File "/home/cudaa/Workspace/software/MKIDPipeline/mkidpipeline/steps/flatcal.py", line 145, in load_flat_spectra
    self.make_spectral_cube()
  File "/home/cudaa/Workspace/software/MKIDPipeline/mkidpipeline/steps/flatcal.py", line 125, in run
    self.load_flat_spectra()
  File "/home/cudaa/Workspace/software/MKIDPipeline/mkidpipeline/steps/flatcal.py", line 564, in fetch
    f.run()
  File "/home/cudaa/Workspace/software/MKIDPipeline/mkidpipeline/mkidpipe.py", line 179, in main
    pipe.PIPELINE_STEPS[step].fetch(getattr(outputs, f"{step}s"))
  File "/home/cudaa/Workspace/software/MKIDPipeline/mkidpipeline/mkidpipe.py", line 192, in mainmain
    return main(args)
           ^^^^^^^^^^
  File "/home/cudaa/Workspace/software/MKIDPipeline/mkidpipeline/mkidpipe.py", line 195, in <module>
    sys.exit(mainmain())
             ^^^^^^^^^^
ValueError: could not broadcast input array from shape (0,140,146) into shape (6,140,146)