I tried to download and run logback demo app described in here:
http://logback.qos.ch/demo.html

After invoking git clone, I tried the "mvn package jetty:run" command, error message appeared:

[INFO]
[INFO] — maven-resources-plugin:2.6:resources (default-resources) @ logback-demo —
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 8 resources
[INFO]
[INFO] — maven-compiler-plugin:3.1:compile (default-compile) @ logback-demo —
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding UTF-8, i.e. build is platform dependent!
[INFO] Compiling 23 source files to /data/Workspace/sandbox-oss/logback-demo/target/classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] /data/Workspace/sandbox-oss/logback-demo/src/main/java/ch/qos/logback/demo/statii/ChooseModuleAction.java:[39,56] cannot access org.eclipse.jetty.server.RequestLog
class file for org.eclipse.jetty.server.RequestLog not found
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 37.332 s
[INFO] Finished at: 2016-02-23T08:22:04+08:00
[INFO] Final Memory: 15M/65M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project logback-demo: Compilation failure
[ERROR] /data/Workspace/sandbox-oss/logback-demo/src/main/java/ch/qos/logback/demo/statii/ChooseModuleAction.java:[39,56] cannot access org.eclipse.jetty.server.RequestLog
[ERROR] class file for org.eclipse.jetty.server.RequestLog not found
[ERROR] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException