altogether obvious:

  * Localhost may be unavailable. Therefore, even locally installed
    server processes which work by conversing over a port may fail.

  * Not all "remote" repositories will fail. Specifically, if the remote
    repo uses the file:// protocol, and it doesn't refer to a shared
    filesystem, it will continue to be available.

      <post>******@****.***</post>
      <archive>http://mail-archives.apache.org/mod_mbox/maven-users</archive>
    </mailingList>
    <mailingList>
      <name>Maven Developer List</name>
      <subscribe>******@****.***</subscribe>
      <unsubscribe>******@****.***</unsubscribe>
      <post>******@****.***</post>
      <archive>http://mail-archives.apache.org/mod_mbox/maven-dev</archive>
    </mailingList>

      <name>Apache Announce List</name>
      <subscribe>******@****.***</subscribe>
      <unsubscribe>******@****.***</unsubscribe>
      <post>******@****.***</post>
      <archive>http://mail-archives.apache.org/mod_mbox/www-announce/</archive>
    </mailingList>
  </mailingLists>

[maven-home]: https://maven.apache.org/
[maven-download]: https://maven.apache.org/download.cgi
[users-list]: https://maven.apache.org/mailing-lists.html
[dev-ml-list]: https://www.mail-archive.com/******@****.***/
[code-style]: http://maven.apache.org/developers/conventions/code.html
[core-it]: https://maven.apache.org/core-its/core-it-suite/

                        <goals>
                            <goal>enforce</goal>
                        </goals>
                        <configuration>
                            <fail>true</fail>
                            <rules>
                                <requireMavenVersion>
                                    <!-- Some plugin features require a recent Maven runtime to work properly -->