Download 1542 war. run java -jar jenkins.jar. stop it. run again. jenkins will show the directory index instead of jenkins, on the browser. on the logs I see winstone being used instead of jetty. clean install.

On success, the logs shows
INFO: Extract jar:file:/opt/110-jenkins/jenkins/jenkins.war!/ to /tmp/jetty-0.0.0.0-8080-jenkins.war-_jenkins-any-/webapp
INFO: Winstone Servlet Engine v2.0 running: controlPort=disabled

On failure, only the second line.

The only way to start it again is to remove ~/.jenkins and /tmp/jenk* and start from scratch.

Unusable.