Aside from the regular (produced by Sphinx, I suppose) build warnings, there are many LaTeX-related ones. They are somehow crippled and uninformative (provide neither full name of the file, nor the exact line). It's not quite clear, what can be done about them.

As an example:
http://tegra-reports.dyndns.org/buildbot/builders/CV-docs-master/builds/78/steps/cvdocs/logs/warnings%20%2898%29