<!-- internal field removed -->
              <exclude>org.apache.maven.graph.DefaultGraphBuilder#projectBuilder</exclude>
              <!-- MavenPluginValidator has been transformed into an interface -->
              <exclude>org.apache.maven.plugin.MavenPluginValidator</exclude>
              <!-- Remove plexus logger -->

            Let's take the warnings for one module, c.g.c.base.testModule, as an example:

              [INFO] Validating units:
              [INFO]    Ignored 53 units with compilation errors in first pass.
              [INFO] Compile with -strict or with -logLevel set to TRACE or DEBUG to see all errors.

                   (Compare what guava-gwt has to do for maven-javadoc-plugin.)
              -->
              <arg>-sourcepath</arg>
              <arg>doesnotexist</arg>
              <!-- https://errorprone.info/docs/installation#maven -->
              <arg>-XDcompilePolicy=simple</arg>
              <!-- -Xplugin:ErrorProne is set conditionally by a profile. -->
            </compilerArgs>
            <annotationProcessorPaths>