title: Javac doesn't work in ant build
body: <p>I try to run javac in ant build.xml on command line on ubuntu 11.02.
  After then running "ant deploy-live", the command line prints like:</p>
  
  <pre><code>Compile failed; see the compiler error output for details.
      at org.apache.tools.ant.taskdefs.Javac.compile(Javac.java:1150)
      at org.apache.tools.ant.taskdefs.Javac.execute(Javac.java:912)
      at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
      at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:616)
      at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
      at org.apache.tools.ant.Task.perform(Task.java:348)
      at org.apache.tools.ant.Target.execute(Target.java:390)
      at org.apache.tools.ant.Target.performTasks(Target.java:411)
      at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1399)
      at org.apache.tools.ant.helper.SingleCheckExecutor.executeTargets(SingleCheckExecutor.java:38)
      at org.apache.tools.ant.Project.executeTargets(Project.java:1251)
      at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:442)
      at org.apache.tools.ant.taskdefs.CallTarget.execute(CallTarget.java:105)
      at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
      at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:616)
      at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
      at org.apache.tools.ant.Task.perform(Task.java:348)
      at org.apache.tools.ant.Target.execute(Target.java:390)
      at org.apache.tools.ant.Target.performTasks(Target.java:411)
      at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1399)
      at org.apache.tools.ant.Project.executeTarget(Project.java:1368)
      at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
      at org.apache.tools.ant.Project.executeTargets(Project.java:1251)
      at org.apache.tools.ant.Main.runBuild(Main.java:809)
      at org.apache.tools.ant.Main.startAnt(Main.java:217)
      at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280)
      at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)
  </code></pre>
  
  <p>My task about javac:</p>
  
  <pre><code>&lt;javac deprecation="true"
                 includeantruntime="false"
                 debug="true"
                 debuglevel="${debuglevel}"
                 destdir="${project.build.outputpath}"
                 verbose="true"
                 encoding="UTF-8"&gt;
              &lt;src path="${project.src.classes}" /&gt;
              &lt;compilerarg value="-Xlint" /&gt;
              &lt;classpath refid="core.classpath" /&gt;
  &lt;/javac&gt;
  </code></pre>
  
  <p><strong>Os:</strong>
  Ubuntu 11.10 (oneiric)</p>
  
  <p><strong>Java version:</strong>
  java version "1.7.0"
  Java(TM) SE Runtime Environment (build 1.7.0-b147)
  Java HotSpot(TM) 64-Bit Server VM (build 21.0-b17, mixed mode)</p>
  
  <p><strong>Ant version:</strong> Apache Ant(TM) version 1.8.2 compiled on August 19 2011</p>
  
  <p>I tried about encoding build.xml file, but couldn't work.</p>
  
  <p>Please help</p>