The normal project layout, generated by the scaffolding for Pyramid projects, generates a project structure like this:

project/
       package/
               tests.py (or tests/*)

In conjunction with Jenkins, it turns out that nose's plugin for Cobertura-style output fails to discover the test modules properly. Instead of saying

$ nosetests --with-xcover

one needs to also specify the configuration file:

$ nosetests -c development.ini  --with-xcover