title: Can't extract module name from some.jar: some.class found in top-level directory (unnamed package not allowed in module)
body: <p>We are migrating our software to Java 9. The application that I am working on uses pretty old Java libraries and there is no opportunity to update them.
  Here is our <code>pom.xml</code> file fragment:</p>
  
  <pre><code>&lt;project&gt;
      &lt;repositories&gt;
          ..our private repositories
      &lt;/repositories&gt;
  
      &lt;build&gt;
          &lt;plugins&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
                  &lt;artifactId&gt;maven-compiler-plugin&lt;/artifactId&gt;
                  &lt;version&gt;3.8.1&lt;/version&gt;
                  &lt;configuration&gt;
                      &lt;source&gt;11&lt;/source&gt;
                      &lt;target&gt;11&lt;/target&gt;
                      &lt;executable&gt;javac10&lt;/executable&gt;
                  &lt;/configuration&gt;
  
              &lt;/plugin&gt;
          &lt;/plugins&gt;
      &lt;/build&gt;
  
      &lt;profiles&gt;
          &lt;profile&gt;
              &lt;id&gt;windows&lt;/id&gt;
              &lt;activation&gt;
                  &lt;os&gt;
                      &lt;family&gt;windows&lt;/family&gt;
                  &lt;/os&gt;
              &lt;/activation&gt;
              &lt;dependencies&gt;
                  &lt;dependency&gt;
                      &lt;groupId&gt;com.latencybusters.lbm&lt;/groupId&gt;
                      &lt;artifactId&gt;UMSJMS&lt;/artifactId&gt;
                      &lt;version&gt;5.3.6&lt;/version&gt;
                      &lt;classifier&gt;windows&lt;/classifier&gt;
                  &lt;/dependency&gt;
              &lt;/dependencies&gt;
          &lt;/profile&gt;
      &lt;/profiles&gt;
  </code></pre>
  
  <p>
  Our current OS is <code>Windows</code>. So the problems is with com.latencybusters.lbm library.</p>
  
  <p><code>Intellij Idea</code> doesn't highlight <code>module-info.java</code> file as well as any other class. So it was expected that the project would get compiled.
  But running <code>mvn clean compile -X</code> returns </p>
  
  <pre><code>...
  [WARNING] Can't extract module name from UMSJMS-5.3.6-windows.jar: lbmmsrc.class found in top-level directory (unnamed package not allowed in module)
  ...
  module-info.java: module not found: UMSJMS
  </code></pre>
  
  <p>What could be the reason of this bug?</p>