title: JaCoCo plugin gives different coverage
body: <p>I'm using the JaCoCo Maven plugin and agent to measure and retrieve the code coverage data of an application which is tested nightly.
  This is the schema of the architecture:</p>
  
  <p><a href="https://i.stack.imgur.com/T7P4Z.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/T7P4Z.png" alt="Tests architecture"></a></p>
  
  <p>My Maven project is configured with the <a href="https://github.com/jmeter-maven-plugin/jmeter-maven-plugin" rel="nofollow noreferrer">JMeter Maven plugin</a> to execute some API tests during the Maven <code>verify</code> phase.
  The Maven command executed by the Jenkins server is the following</p>
  
  <pre><code>mvn verify org.jacoco:jacoco-maven-plugin:0.7.8:dump sonar:sonar -Djacoco.address=TEST_SERVER -Djacoco.destFile=/proj/coverage-reports/jacoco-it.exec -Dsonar.projectKey=sonar_test -Dsonar.projectName=sonar_test -Dsonar.branch=sonar_test -Dsonar.jacoco.itReportPath=/proj/coverage-reports/jacoco-it.exec -Dsonar.java.coveragePlugin=jacoco -Dsonar.language=java
  </code></pre>
  
  <p>As you can see first the tests are executed through the <code>verify</code> phase, then the <code>jacoco:dump</code> goal retrieves the coverage data from the test server (I configured the server to run the JaCoCo agent) and at last the data is uploaded to my Sonar server. </p>
  
  <p>The "strange" behaviour I'm having is that if I run this command on my computer and then on Jenkins (configuring the Jenkins project accordingly) in the SonarQube page I get different coverage results. Moreover, if I configure the Jenkins project and then I simply COPY it creating a new (but equivalent) Jenkins project, the results are different.</p>
  
  <p><a href="https://i.stack.imgur.com/YrM3j.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/YrM3j.png" alt="Coverage result for local test"></a></p>
  
  <p><a href="https://i.stack.imgur.com/en5cS.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/en5cS.png" alt="Coverage result with Jenkins"></a></p>
  
  <p>I tried different configurations and cases, but I cannot understand what the problem can be. Am I not considering some JaCoCo constraints (e.g. someting related to the Jenkins project name)?</p>