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>

                      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>