util.concurrent, like nearly all our packages, has two .gwt.xml files: one
    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages

    util.concurrent, like nearly all our packages, has two .gwt.xml files: one
    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages

    util.concurrent, like nearly all our packages, has two .gwt.xml files: one
    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages

    util.concurrent, like nearly all our packages, has two .gwt.xml files: one
    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages

                   JDK6-like APIs.

                   So instead, we use javac9, which doesn't lead to this error.
              -->
              <compilerArgs combine.children="append">
                <arg>-J-Xbootclasspath/p:${settings.localRepository}/com/google/errorprone/javac/${javac.version}/javac-${javac.version}.jar</arg>
              </compilerArgs>
            </configuration>

  <build>
    <resources>
      <resource>
        <directory>..</directory>
        <includes>
          <include>LICENSE</include> <!-- copied from the parent pom because I couldn't figure out a way to make combine.children="append" work -->
          <include>proguard/*</include>
        </includes>
        <targetPath>META-INF</targetPath>
      </resource>
    </resources>
    <plugins>
      <plugin>

      <plugins>
        <plugin>
          <groupId>org.apache.rat</groupId>
          <artifactId>apache-rat-plugin</artifactId>
          <configuration>
            <excludes combine.children="append">
              <exclude>src/assembly/maven/bin/m2.conf</exclude>
              <!-- these are partial scripts, resulting in mvn scripts -->
              <exclude>src/assembly/shared/init</exclude>