“org.fusesource.scalate.TemplateException：违反加载器约束”使用 SBT 嵌入 Jetty 和 scalatra/scalate 时

Question

我昨天在 SBT 中使用嵌入式“jetty-run”任务时开始收到此错误。我将代码恢复到以前的版本，但它仍然发生。

请注意，我打包了应用程序并将其部署在实际的码头实例中，但没有收到错误。在向我的项目添加一些依赖项（可能相关也可能不相关）后，我开始收到此错误，但后来删除了它们。

我尝试了“clean”、“clean-lib”和“clean-cache”以及清理我的 ~/.m2/repository、~/.ivy2/cache 和 project/boot 目录。

有人还有其他想法吗？

正在爆炸的行是：

templateEngine.layout(uri, Map("flash" -> flash))

更多堆栈跟踪如下：

org.fusesource.scalate.TemplateException: loader constraint violation: when resolving method "scala.tools.nsc.Settings.(Lscala/Function1;)V" the class loader (instance of sbt/jetty/LazyJettyRun7$SbtWebAppLoader$1) of the current class, org/fusesource/scalate/support/ScalaCompiler, and the class loader (instance of java/net/URLClassLoader) for resolved class, scala/tools/nsc/Settings, have different Class objects for the type scala/Function1 used in the signature
    at org.fusesource.scalate.TemplateEngine.compileAndLoad(TemplateEngine.scala:775)
    at org.fusesource.scalate.TemplateEngine.compileAndLoadEntry(TemplateEngine.scala:637)
    at org.fusesource.scalate.TemplateEngine.liftedTree1$1(TemplateEngine.scala:368)
    at org.fusesource.scalate.TemplateEngine.load(TemplateEngine.scala:362)
    at org.fusesource.scalate.TemplateEngine.load(TemplateEngine.scala:420)
    at org.fusesource.scalate.TemplateEngine.layout(TemplateEngine.scala:521)
    at com.ford.testbuilder.web.AppDefaults$class.com$ford$testbuilder$web$AppDefaults$$render(SharedTraits.scala:79)
    at com.ford.testbuilder.web.AppDefaults$$anonfun$6.apply(SharedTraits.scala:52)
    at org.scalatra.ScalatraKernel$$anonfun$handle$1$$anonfun$apply$mcV$sp$1$$anonfun$apply$mcV$sp$2$$anonfun$6.apply(ScalatraKernel.scala:133)
    at org.scalatra.ScalatraKernel$$anonfun$handle$1$$anonfun$apply$mcV$sp$1$$anonfun$apply$mcV$sp$2$$anonfun$6.apply(ScalatraKernel.scala:133)
    at scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:61)
    at scala.collection.immutable.List.foreach(List.scala:45)
    at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:44)
    at scala.collection.mutable.ListBuffer.foreach(ListBuffer.scala:42)
    at org.scalatra.ScalatraKernel$$anonfun$handle$1$$anonfun$apply$mcV$sp$1$$anonfun$apply$mcV$sp$2.apply$mcV$sp(ScalatraKernel.scala:133)
    at org.scalatra.ScalatraKernel$$anonfun$handle$1$$anonfun$apply$mcV$sp$1$$anonfun$apply$mcV$sp$2.apply(ScalatraKernel.scala:121)
    at org.scalatra.ScalatraKernel$$anonfun$handle$1$$anonfun$apply$mcV$sp$1$$anonfun$apply$mcV$sp$2.apply(ScalatraKernel.scala:121)
    at scala.util.DynamicVariable.withValue(DynamicVariable.scala:71)
    at org.scalatra.ScalatraKernel$$anonfun$handle$1$$anonfun$apply$mcV$sp$1.apply$mcV$sp(ScalatraKernel.scala:121)
    at org.scalatra.ScalatraKernel$$anonfun$handle$1$$anonfun$apply$mcV$sp$1.apply(ScalatraKernel.scala:121)
    at org.scalatra.ScalatraKernel$$anonfun$handle$1$$anonfun$apply$mcV$sp$1.apply(ScalatraKernel.scala:121)
    at scala.util.DynamicVariable.withValue(DynamicVariable.scala:71)
    at org.scalatra.ScalatraKernel$$anonfun$handle$1.apply$mcV$sp(ScalatraKernel.scala:120)
    at org.scalatra.ScalatraKernel$$anonfun$handle$1.apply(ScalatraKernel.scala:120)
    at org.scalatra.ScalatraKernel$$anonfun$handle$1.apply(ScalatraKernel.scala:120)
    at scala.util.DynamicVariable.withValue(DynamicVariable.scala:71)
    at org.scalatra.ScalatraKernel$class.handle(ScalatraKernel.scala:119)
    at com.ford.testbuilder.web.LoginServlet.org$scalatra$CookieSupport$$super$handle(LoginServlet.scala:10)
    at org.scalatra.CookieSupport$$anonfun$handle$1$$anonfun$apply$mcV$sp$1.apply$mcV$sp(CookieSupport.scala:102)
    at org.scalatra.CookieSupport$$anonfun$handle$1$$anonfun$apply$mcV$sp$1.apply(CookieSupport.scala:102)
    at org.scalatra.CookieSupport$$anonfun$handle$1$$anonfun$apply$mcV$sp$1.apply(CookieSupport.scala:102)
    at scala.util.DynamicVariable.withValue(DynamicVariable.scala:71)
    at org.scalatra.CookieSupport$$anonfun$handle$1.apply$mcV$sp(CookieSupport.scala:101)
    at org.scalatra.CookieSupport$$anonfun$handle$1.apply(CookieSupport.scala:101)
    at org.scalatra.CookieSupport$$anonfun$handle$1.apply(CookieSupport.scala:101)
    at scala.util.DynamicVariable.withValue(DynamicVariable.scala:71)
    at org.scalatra.CookieSupport$class.handle(CookieSupport.scala:100)
    at com.ford.testbuilder.web.LoginServlet.org$scalatra$FlashMapSupport$$super$handle(LoginServlet.scala:10)
    at org.scalatra.FlashMapSupport$$anonfun$handle$1.apply$mcV$sp(flashMap.scala:101)
    at org.scalatra.FlashMapSupport$$anonfun$handle$1.apply(flashMap.scala:100)
    at org.scalatra.FlashMapSupport$$anonfun$handle$1.apply(flashMap.scala:100)
    at scala.util.DynamicVariable.withValue(DynamicVariable.scala:71)
    at org.scalatra.FlashMapSupport$class.handle(flashMap.scala:100)

Answer 1

在尝试在别人的机器上进行新的检查（工作正常）并比较类路径后，我发现了这一点。我发现我的类路径中既有 scala-library-2.8.1.jar 又有 scala-library.jar 。

这是由我的项目文件中的以下行引起的：

override def filterScalaJars = false

在此浪费了一天的大部分时间:(