Resolving Maven "trustAnchors parameter must be non-empty" error

I encountered this Maven error on a new Ubuntu 18.04 system while trying to perform a mvn build on a Google AppEngine project. A screenshot of the error message is shown below.

It seems to be complaining about some "java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty" error.

After trying out some suggestions about regenerating Java security certificates, which didn't work, I managed to resolve the problem by creating a Maven  settings.xml file under a hidden folder .m2 underneath the user's home directory.

An example settings.xml file is shown below.

<?xml version="1.0" encoding="UTF-8"?>
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0                            http://maven.apache.org/xsd/settings-1.0.0.xsd">
   <localRepository>/home/yourname/.m2/repository</localRepository>
   <interactiveMode />
   <usePluginRegistry />
   <offline />
   <pluginGroups />
   <servers />
   <mirrors />
   <proxies>
      <!-- 
               <proxy>
      <id>default</id>
      <active>true</active>
      <protocol>http</protocol>
      <host>proxy-host</host>
      <port>8080</port>
      <username>user</username>
      <password>password123</password>
      <nonProxyHosts>localhost,127.0.0.1</nonProxyHosts>
    </proxy> -->
   </proxies>
   <activeProfiles>
      <!--make the profile active all the time -->
      <activeProfile>securecentral</activeProfile>
   </activeProfiles>
   <profiles>
      <profile>
         <id>securecentral</id>
         <!--Override the repository (and pluginRepository) "central" from the
                     Maven Super POM -->
         <repositories>
            <repository>
               <id>central</id>
               <url>http://repo1.maven.apache.org/maven2/</url>
               <releases>
                  <enabled>true</enabled>
               </releases>
            </repository>
         </repositories>
         <pluginRepositories>
            <pluginRepository>
               <id>central</id>
               <url>http://repo1.maven.apache.org/maven2/</url>
               <releases>
                  <enabled>true</enabled>
               </releases>
            </pluginRepository>
         </pluginRepositories>
      </profile>
   </profiles>
</settings>

Change the localRepository tag from /home/yourname/.m2/repository to correct location of your Maven repository.

Then place this the settings.xml file in the following location /home/your_user_id/.m2/

Now when running Maven build commands, the error messages no longer appear.