title: mvn compilation error LifecycleExecutionException
body: <p>I've installed maven by adding it to my path. When I run the command <code>mvn -v</code> it returns:</p>
  
  <pre><code>Apache Maven 3.5.2 (138edd61fd100ec658bfa2d307c43b76940a5d7d; 2017-10-18T10:58:13+03:00) 
  Maven home: /Users/yarkoni/apache-maven-3.5.2 Java version: 9, vendor: Oracle Corporation 
  Java home: /Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home 
  Default locale: en_US, platform encoding: UTF-8 OS name: "mac os x", 
  version: "10.12.6", arch: "x86_64", family: "mac"
  </code></pre>
  
  <p>To my understand in order to install I downloaded and added it to my PATH.
  I then try to runt he example appEngine app locally:</p>
  
  <pre><code>mvn -Plocal clean appengine:devserver
  </code></pre>
  
  <p>I get the following error:</p>
  
  <pre><code>    [INFO] Compiling 11 source files to /Users/yarkoni/Projects/getting-started-java/bookshelf-standard/2-structured-data/target/bookshelf-standard-2-1.0-SNAPSHOT/WEB-INF/classes An exception has occurred in the compiler (9-internal). 
  Please file a bug against the Java compiler via the Java bug reporting page (http://bugreport.java.com) after checking the Bug Database (http://bugs.java.com) for duplicates. Include your program and the following diagnostic in your report. Thank you.
  java.io.UncheckedIOException: java.nio.file.NotDirectoryException: /Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home/lib/modules
      at com.sun.tools.javac.file.Locations$BootClassPathLocationHandler.lazy(Locations.java:712)
      at com.sun.tools.javac.file.Locations$BootClassPathLocationHandler.isDefault(Locations.java:546)
      at com.sun.tools.javac.file.Locations.isDefaultBootClassPath(Locations.java:126)
      at com.sun.tools.javac.file.BaseFileManager.isDefaultBootClassPath(BaseFileManager.java:204)
      at com.sun.tools.javac.main.Arguments.validate(Arguments.java:479)
      at com.sun.tools.javac.api.JavacTaskImpl.prepareCompiler(JavacTaskImpl.java:168)
      at com.sun.tools.javac.api.JavacTaskImpl.access$000(JavacTaskImpl.java:69)
      at com.sun.tools.javac.api.JavacTaskImpl$1.call(JavacTaskImpl.java:96)
      at com.sun.tools.javac.api.JavacTaskImpl$1.call(JavacTaskImpl.java:93)
      at com.sun.tools.javac.api.JavacTaskImpl.handleExceptions(JavacTaskImpl.java:128)
      at com.sun.tools.javac.api.JavacTaskImpl.doCall(JavacTaskImpl.java:93)
      at com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:87)
      at com.google.errorprone.BaseErrorProneJavaCompiler$1.call(BaseErrorProneJavaCompiler.java:99)
      at com.google.errorprone.BaseErrorProneCompiler.run(BaseErrorProneCompiler.java:137)
      at com.google.errorprone.BaseErrorProneCompiler.run(BaseErrorProneCompiler.java:108)
      at com.google.errorprone.ErrorProneCompiler.run(ErrorProneCompiler.java:119)
      at org.codehaus.plexus.compiler.javac.errorprone.JavacCompilerWithErrorProne$CompilerInvoker.compile(JavacCompilerWithErrorProne.java:222)
      at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.base/java.lang.reflect.Method.invoke(Method.java:564)
      at org.codehaus.plexus.compiler.javac.errorprone.JavacCompilerWithErrorProne.performCompile(JavacCompilerWithErrorProne.java:91)
      at org.apache.maven.plugin.compiler.AbstractCompilerMojo.execute(AbstractCompilerMojo.java:943)
      at org.apache.maven.plugin.compiler.CompilerMojo.execute(CompilerMojo.java:137)
      at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:154)
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:146)
      at org.apache.maven.lifecycle.internal.MojoExecutor.executeForkedExecutions(MojoExecutor.java:353)
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:198)
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:154)
      at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:146)
      at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
      at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:81)
      at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
      at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
      at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:309)
      at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:194)
      at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:107)
      at org.apache.maven.cli.MavenCli.execute(MavenCli.java:955)
      at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:290)
      at org.apache.maven.cli.MavenCli.main(MavenCli.java:194)
      at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.base/java.lang.reflect.Method.invoke(Method.java:564)
      at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
      at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
      at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
      at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356) Caused by: java.nio.file.NotDirectoryException: /Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home/lib/modules
      at java.base/sun.nio.fs.UnixFileSystemProvider.newDirectoryStream(UnixFileSystemProvider.java:407)
      at java.base/java.nio.file.Files.newDirectoryStream(Files.java:465)
      at java.base/java.nio.file.Files.list(Files.java:3524)
      at com.sun.tools.javac.file.Locations$BootClassPathLocationHandler.systemClasses(Locations.java:665)
      at com.sun.tools.javac.file.Locations$BootClassPathLocationHandler.computePath(Locations.java:621)
      at com.sun.tools.javac.file.Locations$BootClassPathLocationHandler.lazy(Locations.java:709)     ... 49 more
  </code></pre>