/usr/share/sphinx_rtd_theme/static/fonts/Lato-Regular.ttf is in sphinx-rtd-theme-common 0.2.4-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/sphinx_rtd_theme/static/fonts/../../../fonts/truetype/lato/Lato-Regular.ttf