Lid-driven cavity example fails

473/480 Test #480: example_ff_liddrivencavity_plot ............................***Failed    0.27 sec
Traceback (most recent call last):
  File "/data/build/dumux/examples/liddrivencavity/run_and_plot.py", line 50, in <module>
    import matplotlib.pyplot as plt
ModuleNotFoundError: No module named 'matplotlib'