I am running Java 8. I am executing the tests from the command line as:
mvn surefire:test -Psurefire -Dgroups="downloadWars"
WARNING] Couldn't load group class 'downloadWars' in Surefire|Failsafe plugin. The group class is ignored!
This works fine with the version set to 2.22.0. Here is the pom entry.
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>3.1.0</version>
<executions>
<execution>
<phase>integration-test</phase>
<goals>
<goal>test</goal>
</goals>
<configuration>
<excludes>
<exclude>none</exclude>
</excludes>
<includes>
<include>**/*IntegrationTest</include>
</includes>
</configuration>
</execution>
</executions>
</plugin>
The surefire documentation says that this should still work. I tried 3.2.5 as specified in the documentation as well.