});
        sourcesPath.setCanBeConsumed(false);
        sourcesPath.setCanBeResolved(true);
        sourcesPath.extendsFrom(runtimeClasspath);

        extension.getClasspath().from(runtimeClasspath);
        extension.getSourceRoots().from(sourcesPath.getIncoming().artifactView(v -> v.lenient(true)).getFiles());

            String existing = sourceState.get();
            if (!Files.exists(target) || !Objects.equals(current, existing)) {
                pomArtifactTransformer.transform(project, session, src, target);
                Files.setLastModifiedTime(target, Files.getLastModifiedTime(src.getPath()));
            }
            result = current;
        }
        sourceState.set(result);
        return result;
    }

        builder.setProperty("project.buildpath", validClasspath.asPath)
        builder.setClasspath(validClasspath.files.toTypedArray())

        val validSourcepath = sourcepath.filter { it.exists() }
        builder.setProperty("project.sourcepath", validSourcepath.asPath)
        builder.setSourcepath(validSourcepath.files.toTypedArray())

        val builtJar = builder.build()
        if (!builder.isOk) {

          </sourceFileExcludes>
          <!-- The above exclusion doesn't actually matter unless I prevent Javadoc from autodiscovering the source in the sourcepath, which defaults to the source directory :\ Boo for -sourcepath. -->
          <sourcepath>doesnotexist</sourcepath>

                base compile settings (in the root `pom.xml`) to enable MRJAR output.
              -->
              <compilerArgs combine.self="override">
                <arg>-sourcepath</arg>
                <arg>${project.basedir}/src</arg>
                <arg>--add-reads=com.google.common=ALL-UNNAMED</arg>
                <!-- https://errorprone.info/docs/installation#maven -->

                base compile settings (in the root `pom.xml`) to enable MRJAR output.
              -->
              <compilerArgs combine.self="override">
                <arg>-sourcepath</arg>
                <arg>${project.basedir}/src</arg>
                <arg>--add-reads=com.google.common=ALL-UNNAMED</arg>
                <!-- https://errorprone.info/docs/installation#maven -->

                      https://issues.apache.org/jira/browse/MCOMPILER-174
                      (Compare what guava-gwt has to do for maven-javadoc-plugin.)
                  -->
                  <arg>-sourcepath</arg>
                  <arg>doesnotexist</arg>
                </compilerArgs>
              </configuration>
            </execution>
            <execution>
              <id>default-testCompile</id>