#!/usr/bin/env python3
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.add_subplot(111, frameon=True)
ax.plot()

# If the call to draw() below is removed, everything works
# However, this line cases xtick and ytick get_window_extent()
# to raise 'RuntimeError: Cannot get window extent w/o renderer'
# on matplotlib 2.2.0 (tested also on 2.2.2)
#
# Moreover, this works just fine with and without the call to
# draw() below, with matplotlib 2.1.2
plt.get_current_fig_manager().canvas.draw()

ax.set_xlabel(ax.get_xlabel()).get_window_extent()
ax.set_ylabel(ax.get_ylabel()).get_window_extent()
for xtick in ax.get_xticklabels():
    xtick.get_window_extent()
for ytick in ax.get_yticklabels():
    ytick.get_window_extent()