title: Cannot change Maven version in Eclipse IDE
body: <p>After failing to mvn package inside of Eclipse but succeeding in the terminal, I realized that Eclipse was running <strong>Maven 3.3.3</strong> while terminal was running <strong>3.3.9</strong>. I attempted, and by all apparent accounts succeeded, to reconfigure eclipse by going to <code>Eclipse -&gt; Preferences -&gt; Maven -&gt; Installations</code> and pointing to my <strong>3.3.9</strong> folder. I restarted Eclipse and tried again but to no available. Also, changes to the <code>pom.xml</code> file are not acknowledged when attempting to build. I've inserted inappropriate slashes and other characters and am only able to generate this error:</p>
  
  <p>Error assembling WAR: web.xml attribute is required (or pre-existing WEB-INF/web.xml if executing in update mode)</p>
  
  <p>I modified my pom file as per <a href="https://stackoverflow.com/questions/5351948/webxml-attribute-is-required-error-in-maven">this</a> recommendation but as I said, maven is not recognizing changes to the pom and I cannot get running <code>mvn --version</code> to produce <strong>3.3.9</strong> as it should. I've attached my <code>pom.xml</code> below</p>
  
  <pre><code>&lt;project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"&gt;
  &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
  &lt;groupId&gt;com.javawebtutor&lt;/groupId&gt;
  &lt;artifactId&gt;LoginWebApp&lt;/artifactId&gt;
  &lt;packaging&gt;war&lt;/packaging&gt;
  &lt;version&gt;1.0-SNAPSHOT&lt;/version&gt;
  &lt;name&gt;LoginWebApp Maven Webapp&lt;/name&gt;
  &lt;url&gt;http://maven.apache.org&lt;/url&gt;
  &lt;dependencies&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;javax.servlet&lt;/groupId&gt;
          &lt;artifactId&gt;servlet-api&lt;/artifactId&gt;
          &lt;version&gt;2.5&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;mysql&lt;/groupId&gt;
          &lt;artifactId&gt;mysql-connector-java&lt;/artifactId&gt;
          &lt;version&gt;5.1.30&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;junit&lt;/groupId&gt;
          &lt;artifactId&gt;junit&lt;/artifactId&gt;
          &lt;version&gt;4.10&lt;/version&gt;
      &lt;/dependency&gt;
  &lt;/dependencies&gt;
  &lt;build&gt;
      &lt;finalName&gt;LoginWebApp&lt;/finalName&gt;
      &lt;plugins&gt;
      &lt;plugin&gt;            
        &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
        &lt;artifactId&gt;maven-war-plugin&lt;/artifactId&gt;
        &lt;configuration&gt;
          &lt;webXml&gt;src\main\webapp\WEB-INF\web.xml&lt;/webXml&gt;        
        &lt;/configuration&gt;
      &lt;/plugin&gt;
      &lt;/plugins&gt;
  &lt;/build&gt;
  </code></pre>
  
  <p></p>