Matplotlib font_manager.py font finding error

Question

On a Ubuntu 12.04 machine, whenever I plot something I get an error like:

/usr/lib/pymodules/python2.7/matplotlib/font_manager.py:1228: UserWarning: findfont: Could not match :family=Bitstream Vera Sans:style=normal:variant=normal:weight=medium:stretch=normal:size=x-large. Returning /usr/share/matplotlib/mpl-data/fonts/ttf/cmb10.ttf

which I cannot find a solution to online. The following code reproduces the error

import pylab as plt
plt.plot(np.random.random((128)))
plt.title("This should be monospaced")
plt.savefig("/tmp/testfig.pdf")

and also the matplotlib self test gives this error:

python -c "import matplotlib as m ; m.test(verbosity=1)"

In ~/.matplotlib/matplotlibrc I have:

font.family         : monospace
font.style          : normal
font.variant        : normal
font.weight         : medium
font.stretch        : normal
font.size           : 10.0
font.serif          : Palatino, Bitstream Vera Serif, New Century Schoolbook, Century Schoolbook L, Utopia, ITC Bookman, Bookman, Nimbus Roman No9 L, Times New Roman, Times, Charter, serif
font.sans-serif     : Helvetica, Bitstream Vera Sans, sans-serif
font.monospace      : Monaco, Ubuntu Mono Regular, Bitstream Vera Sans Mono, Andale Mono, Nimbus Mono L, Fixed, Terminal, monospace

Some things that do not solve the problem for me:

1. Delete files in ~/.matplotlib/ (i.e. matplotlibrc, fontList.cache, tex.cache/)
2. Change the font.family property in ~/.matplotlib/matplotlibrc
3. Re-install matplotlib after an apt-get purge

The versions I use are:

• matplotlib 1.1.1~rc1+git20120423-0ubuntu1
• Python 2.7.3
• IPython 0.12.1
• Ubuntu 12.04

Answer 1

After some fiddling around with font packages, the solution for me was installing the following packages:

libsys-cpu-perl pcf2bdf tex-gyre ttf-bitstream-vera tv-fonts xfonts-traditional

I'm not sure why this helps, so perhaps somebody can add some background as to why this helps. Hopefully this helps someone else.