The xml which is produced by the //coverage xml// command doesn't produce the sources element.
This disturbs me when I run //coverage xml// in Hudson and the coverage.xml file is not located in the workspace directory, causing the filenames to appear in a relative location - not to the workspace directory.
To solve the issue I needed to produce the coverage report from the workspace directory.
Checking out the Cobertura project and running the example, I saw that there is a special element called: "sources" that has the directory of the source files.
I think that //coverage xml// should get b basedir or something and produce the sources element accordingly, just like Cobertura does.