facet_grid: Internal error

[IKupriyanov-HORIS]

Crash with internal error when try to run this code snippet:

from lets_plot import *
LetsPlot.setup_html()

data = {
    'x': [0, 0, 1, 1, 0, 0, 1, 1],
    'f': ['A', 'B', 'B', 'A', 'B', 'A', 'A', 'B'],
    'g': ['X', 'X', 'X', 'X', 'Y', 'Y', 'Y', 'Y'],
    'p': ['q', 'q', 'q', 'w', 'w', 'w', 'w', 'w']
}

ggplot(data) + \
    geom_bar(aes(x='x', fill='f')) + \
    facet_grid(x='g', y='p')

Output:

ERR [BackendSpecTransformUtil] : Internal error: IndexOutOfBoundsException : Empty list doesn't contain element at index 0.
Internal error: IndexOutOfBoundsException : Empty list doesn't contain element at index 0.