It seems there is a bug either in the book, the game-of-life project, or Jenkins 1.500. As it is hard to track where the bug is caused for a Jenkins beginner, I am posting it here so you can decide.

When enabling cobertura publishing as described on page 37 of chapter 2, using the recommended default path found in both the book's screenshot and the Jenkins GUI (**/target/site/cobertura/coverage.xml), the result is that the cobertura tests works fine but Jenkins does not find the coverage.xml file.

I checked the workspace and actually the file is not there, but Maven says cobertura actually did process files:

[INFO] --- cobertura-maven-plugin:2.5.2:cobertura (default-cli) @ gameoflife-web ---
[INFO] Cobertura 1.9.4.1 - GNU GPL License (NO WARRANTY) - See COPYRIGHT file
Cobertura: Loaded information on 2 classes.
Report time: 191ms

[INFO] Cobertura Report generation was successful.
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] gameoflife ........................................ SUCCESS [10.518s]
[INFO] gameoflife-build .................................. SUCCESS [0.302s]
[INFO] gameoflife-core ................................... SUCCESS [1.909s]
[INFO] gameoflife-web .................................... SUCCESS [1.780s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 15.726s
[INFO] Finished at: Mon Feb 04 17:46:31 CET 2013
[INFO] Final Memory: 16M/39M
[INFO] ------------------------------------------------------------------------
Veröffentliche Javadocs
Zeichne Testergebnisse auf.
[Cobertura] Publishing Cobertura coverage report...
[Cobertura] No coverage results were found using the pattern '**/target/site/cobertura/coverage.xml' relative to '/usr/share/tomcat6/.jenkins/workspace/gameoflife-default'. Did you enter a pattern relative to the correct directory? Did you generate the XML report(s) for Cobertura?
Build step 'Veröffentliche die Cobertura Testabdeckung' changed build result to FAILURE
Finished: FAILURE