我有一个目标为 Google API 级别 15 的 Android 项目，我可以使用 Ant 在我的机器上成功构建它。但是，问题是，当我尝试在我的 jenkins 服务器上构建它时，出现以下异常：
build.xml:539: java.lang.NullPointerException
at com.android.sdklib.SdkManager.loadPlatforms(SdkManager.java:467)
at com.android.sdklib.SdkManager.reloadSdk(SdkManager.java:151)
at com.android.sdklib.SdkManager.createManager(SdkManager.java:132)
at com.android.ant.GetTargetTask.execute(GetTargetTask.java:121)
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:1360)
at org.apache.tools.ant.Project.executeTarget(Project.java:1329)
at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
at org.apache.tools.ant.Project.executeTargets(Project.java:1212)
at org.apache.tools.ant.Main.runBuild(Main.java:801)
at org.apache.tools.ant.Main.startAnt(Main.java:218)
at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280)
at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)
我已经在我的 Jenkins 服务器上安装了 Google API 级别 15。任何想法可能会发生什么？