title: maven-checkstyle-plugin not working with google_checks.xml on macOS
body: <p>I have a Java / Maven project that I build at home with Windows and was executing checkstyle properly. It's using the builtin ruleset, but I tried an external file as well.</p>
  
  <p>Checking out the same code / pom.xml it doesn't seem to work with macOS. The odd thing is if I use the <code>sun_checks.xml</code> it's working fine. Using 8.8 didn't make a difference.</p>
  
  <pre><code>&lt;plugin&gt;
    &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
    &lt;artifactId&gt;maven-checkstyle-plugin&lt;/artifactId&gt;
    &lt;version&gt;3.0.0&lt;/version&gt;
    &lt;dependencies&gt;
      &lt;dependency&gt;
        &lt;groupId&gt;com.puppycrawl.tools&lt;/groupId&gt;
        &lt;artifactId&gt;checkstyle&lt;/artifactId&gt;
        &lt;version&gt;8.7&lt;/version&gt;
      &lt;/dependency&gt;
    &lt;/dependencies&gt;
    &lt;configuration&gt;
      &lt;encoding&gt;UTF-8&lt;/encoding&gt;
      &lt;configLocation&gt;google_checks.xml&lt;/configLocation&gt;
    &lt;/configuration&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p>If I run it like that, it will just complete without doing any checks:</p>
  
  <pre><code>mvn checkstyle:check -X
  Apache Maven 3.5.2 (138edd61fd100ec658bfa2d307c43b76940a5d7d; 2017-10-18T18:58:13+11:00)
  Maven home: /gdev/apache-maven
  Java version: 1.8.0_161, vendor: Oracle Corporation
  Java home: /Library/Java/JavaVirtualMachines/jdk1.8.0_161.jdk/Contents/Home/jre
  Default locale: en_AU, platform encoding: UTF-8
  OS name: "mac os x", version: "10.13.3", arch: "x86_64", family: "mac"
  [..]
  [DEBUG] The resource 'google_checks.xml' was found as jar:file:/Users/udoheld/.m2/repository/com/puppycrawl/tools/checkstyle/8.7/checkstyle-8.7.jar!/google_checks.xml.
  [DEBUG] headerLocation LICENSE.txt
  [DEBUG] JarResourceLoader : trying to load "jar:file:/Users/udoheld/.m2/repository/com/puppycrawl/tools/checkstyle/8.7/checkstyle-8.7.jar"
  [..]
  [DEBUG] Unable to process header location: LICENSE.txt
  [DEBUG] Checkstyle will throw exception if ${checkstyle.header.file} is used
  [INFO] ------------------------------------------------------------------------
  [INFO] BUILD SUCCESS
  </code></pre>
  
  <p>If I run the same with the sun checks:</p>
  
  <pre><code>[..]
  [DEBUG] The resource 'sun_checks.xml' was found as jar:file:/Users/udoheld/.m2/repository/com/puppycrawl/tools/checkstyle/8.7/checkstyle-8.7.jar!/sun_checks.xml.
  [DEBUG] headerLocation LICENSE.txt
  [DEBUG] JarResourceLoader : trying to load "jar:file:/Users/udoheld/.m2/repository/com/puppycrawl/tools/checkstyle/8.7/checkstyle-8.7.jar"
  [..]
  [DEBUG] Checkstyle will throw exception if ${checkstyle.header.file} is used
  [INFO] There are 7 errors reported by Checkstyle 8.7 with sun_checks.xml ruleset.
  [ERROR] src/main/java/com/udoheld/Test.java:[0] (javadoc) JavadocPackage: Missing package-info.java file.
  </code></pre>
  
  <p>Trying the checkstyle on the commandline without using maven seems to work as well <code>java -jar ~/Downloads/checkstyle-8.8/checkstyle-8.8-all.jar -c ../checkstyle-google.xml *</code>:</p>
  
  <pre><code>Starting audit...
  [WARN] /gdev/git/test/src/main/java/com/udoheld/Test.java:18: Comment has incorrect indentation level 4, expected is 6, indentation should be the same level as line 19. [CommentsIndentation]
  </code></pre>
  
  <p>As the logs show I'm using Maven 3.5.2 on macOS 10.13.3 with Java 1.8.0_161 64 Bit.</p>
  
  <p>How do I get the maven-checkstyle-plugin working with the google ruleset on macOS?</p>