Jenkins fails to start when both libservlet2.5 and libservlet2.4 are installed.
Jenkins itself only depend on the 2.4 version.
The presence of libservlet2.5 causes the following error:
Running from: /usr/share/jenkins/jenkins.war
[Winstone 2011/08/16 20:27:41] - Beginning extraction from war file
[Winstone 2011/08/16 20:27:41] - XML Error (Line 67): schema_reference.4: Failed to read schema document 'jar:file:/usr/share/java/servlet-api-2.5.jar!/javax/servlet/resources/javaee_5.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.
[Winstone 2011/08/16 20:27:41] - XML Error (Line 68): schema_reference.4: Failed to read schema document 'jar:file:/usr/share/java/servlet-api-2.5.jar!/javax/servlet/resources/jsp_2_1.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.
[Winstone 2011/08/16 20:27:42] - XML Error (Line 82): schema_reference.4: Failed to read schema document 'jar:file:/usr/share/java/servlet-api-2.5.jar!/javax/servlet/resources/jsp_2_0.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.
[Winstone 2011/08/16 20:27:43] - XML Error (Line 26): Document is invalid: no grammar found.
[Winstone 2011/08/16 20:27:43] - XML Error (Line 26): Document root element "web-app", must match DOCTYPE root "null".
[Winstone 2011/08/16 20:27:44] - Container startup failed
java.lang.ClassCastException: hudson.util.CharacterEncodingFilter cannot be cast to javax.servlet.Filter
at winstone.FilterConfiguration.getFilter(FilterConfiguration.java:128)
at winstone.WebAppConfiguration.<init>(WebAppConfiguration.java:915)
at winstone.HostConfiguration.initWebApp(HostConfiguration.java:131)
at winstone.HostConfiguration.<init>(HostConfiguration.java:73)
at winstone.HostGroup.initHost(HostGroup.java:85)
at winstone.HostGroup.<init>(HostGroup.java:45)
at winstone.Launcher.<init>(Launcher.java:196)
at winstone.Launcher.main(Launcher.java:391)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at Main._main(Main.java:248)
at Main.main(Main.java:95)
A simple remove of the offending 2.5 package made jenkins happy again.
sudo apt-get remove libservlet2.5-java
/etc/init.d/jenkins restart
Confirmed - easily to reproduce
jenkins-winstone bundled xsd and dtd for various specifications but they where older versions with non-free copyright statements so where removed from the upstream tarball and the package is built against servlet and jsp jar files already in the archive containing these resources.
However the jsp jar file is missing from the Classpath manifest entry; it may be that having these external to the winstone.jar file does not work that well either.
I'll take a look and see which is the best way forward on this as it would be possible to patch in the CDDL/GPL distributed versions of these files if required.