<plugin>
          <groupId>org.codehaus.mojo</groupId>
          <artifactId>build-helper-maven-plugin</artifactId>
          <version>3.0.0</version>
          <executions>
              <execution>
                  <phase>generate-sources</
 
phase>
                  <goals>
                      <goal>add-source</goal>
                  </goals>
                  <configuration>
                      <sources>
                          <source>${project.build.directory}/generated-sources/avro/</
 
source>
                      </sources>
                  </configuration>
              </execution>
          </executions>
      </plugin>

build-helper-maven-plugin