Occurs in Bamboo, for instance.
2013-07-15 12:16:10,250 ERROR [http-9087-Processor12] [[default]] Servlet.service() for servlet default threw exception java.lang.ClassFormatError: Illegal class name "com/google/common/collect/package-info" in class file com/google/common/collect/package-info at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631) at java.lang.ClassLoader.defineClass(ClassLoader.java:615) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141) at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:1876) at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:889) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1353) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1232) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:249) at java.lang.Package.getPackageInfo(Package.java:352) at java.lang.Package.getAnnotation(Package.java:367) at org.codehaus.jackson.xc.JaxbAnnotationIntrospector.findAnnotation(JaxbAnnotationIntrospector.java:885) at org.codehaus.jackson.xc.JaxbAnnotationIntrospector.findAccessType(JaxbAnnotationIntrospector.java:265) at org.codehaus.jackson.xc.JaxbAnnotationIntrospector.findAutoDetectVisibility(JaxbAnnotationIntrospector.java:216) at org.codehaus.jackson.map.AnnotationIntrospector$Pair.findAutoDetectVisibility(AnnotationIntrospector.java:1018)