matplotlib error in plot generation

[ijhoskins]

I experienced an issue with matplotlib when generating plots.

enrich_cmd /scratch/users/ihoskins/variant_call_compare/enrich/CBS_pAG415GAL_tile6_test.json counts wt
2021-12-09 01:30:40,801 [enrich2.main] Detected a OverlapSeqLib config file

...

2021-12-09 02:00:17,820 [enrich2.overlap.OverlapSeqLib - wt_nonselect_tile6_test] Creating plots
Traceback (most recent call last):
  File "/home/ihoskins/miniconda3/envs/enrich2/bin/enrich_cmd", line 11, in <module>
    load_entry_point('Enrich2==1.3.1', 'console_scripts', 'enrich_cmd')()
  File "build/bdist.linux-x86_64/egg/enrich2/main.py", line 231, in main_cmd
  File "build/bdist.linux-x86_64/egg/enrich2/overlap.py", line 335, in make_plots
  File "build/bdist.linux-x86_64/egg/enrich2/seqlib.py", line 335, in make_plots
  File "build/bdist.linux-x86_64/egg/enrich2/plots.py", line 418, in counts_plot
  File "/home/ihoskins/miniconda3/envs/enrich2/lib/python2.7/site-packages/matplotlib/pyplot.py", line 1184, in subplots
    fig = figure(**fig_kw)
  File "/home/ihoskins/miniconda3/envs/enrich2/lib/python2.7/site-packages/matplotlib/pyplot.py", line 533, in figure
    **kwargs)
  File "/home/ihoskins/miniconda3/envs/enrich2/lib/python2.7/site-packages/matplotlib/backend_bases.py", line 161, in new_figure_manager
    return cls.new_figure_manager_given_figure(num, fig)
  File "/home/ihoskins/miniconda3/envs/enrich2/lib/python2.7/site-packages/matplotlib/backend_bases.py", line 167, in new_figure_manager_given_figure
    canvas = cls.FigureCanvas(figure)
  File "/home/ihoskins/miniconda3/envs/enrich2/lib/python2.7/site-packages/matplotlib/backends/backend_qt5agg.py", line 24, in __init__
    super(FigureCanvasQTAgg, self).__init__(figure=figure)
  File "/home/ihoskins/miniconda3/envs/enrich2/lib/python2.7/site-packages/matplotlib/backends/backend_qt5.py", line 234, in __init__
    _create_qApp()
  File "/home/ihoskins/miniconda3/envs/enrich2/lib/python2.7/site-packages/matplotlib/backends/backend_qt5.py", line 125, in _create_qApp
    raise RuntimeError('Invalid DISPLAY variable')
RuntimeError: Invalid DISPLAY variable

This looks pertinent: https://stackoverflow.com/questions/35737116/runtimeerror-invalid-display-variable

I'm running on:
Linux Mozart 5.11.0-34-generic 36~20.04.1-Ubuntu SMP Fri Aug 27 08:06:32 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

Is there a way to disable plot generation? Unfortunately this must be before writing final results as I do not see the Results directory (only a plots directory with a corrupt counts.pdf file).