Bug report

Bug summary

While trying to save a plot containing special characters as an SVG image, I get an error message saying the glyph cannot be converted with the encoding and may be wrong. In the produced SVG file, the special character is displayed as a rectangle with a cross. I searched a bit online and found the solution to this problem was to set svg.fonttype to 'none' in matplotlibrc. When I do this, however, it appears that matplotlibrc cannot handle the single quotes around 'none', although the default (commented out) option 'path' is in quotes. If I write just none without quotes, I continue to get the same error message.

Code for reproduction

import matplotlib.pyplot as plt
plt.rcParams['text.usetex'] = True
plt.rcParams['text.latex.preamble'] = '\usepackage{siunitx},\usepackage{libertine}'
plt.xlabel(r'$\si{\degree}$')
plt.tight_layout()
plt.savefig('plot.svg')
plt.show()

Actual outcome

/usr/local/lib/python2.7/dist-packages/matplotlib/textpath.py:385: UserWarning: The glyph (176) of font (/usr/share/texmf/fonts/type1/public/cm-super/sfrm3583.pfb) cannot be converted with the encoding. Glyph may be wrong

Expected outcome

Ideally, the SVG file should contain a plot with the x-axis labeled with a degree sign.

Matplotlib version

• Matplotlib version 2.0.0
• Python version 2.7.12
• Platform Linux Mint 18.1
• Python installed from Linux Mint repos
• Matplotlib installed using pip