<plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <executions>
            <execution>
              <id>test-jar</id>
              <phase>test-compile</phase>
              <goals>
                <goal>test-jar</goal>
              </goals>
            </execution>
          </executions>
        </plugin>

<dependency>
    <groupId>com.example</groupId>
    <artifactId>foo</artifactId>
    <version>1.0.0-SNAPSHOT</version>
</dependency>

<profile>
    <id>local</id>
    <dependencies>
        <dependency>
            <groupId>com.example</groupId>
            <artifactId>foo</artifactId>
            <version>1.0.0-SNAPSHOT</version>
            <type>test-jar</type>
        </dependency>
    </dependencies>
</profile>

<execution>
  <id>local-build</id>
  <phase>package</phase>
  <goals>
    <goal>jar</goal>
  </goals>
  <configuration>
    <classifier>batman</classifier>
    <directory>${basedir}/src/test/java</directory> <!-- tried several variations here -->
    <includes>
        <include>**</include>
    </includes>
  </configuration>
</execution>

<project>
    <groupId>com.example</groupId>
    <artifactId>foo</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <build>
        <plugins>
            ...
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>test-jar</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

<dependency>
    <groupId>com.example</groupId>
    <artifactId>foo</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <type>test-jar</type>
    <!-- uncomment if needed in test scope only
         <scope>test</scope>
    -->
</dependency>

<dependency>
    <groupId>com.example</groupId>
    <artifactId>foo</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <classifier>tests</classifier>
    <scope>test</scope>
</dependency>

<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <!-- used to package the dummy daos when building
         with the local profile -->
    <artifactId>build-helper-maven-plugin</artifactId>
    <executions>
        <execution>
            <phase>generate-sources</phase>
            <goals>
                <goal>add-source</goal>
            </goals>
            <configuration>
                <sources>
                    <source>${extra.sources.dir}</source>
                </sources>
            </configuration>
        </execution>
    </executions>
</plugin>

<profile>
    <id>local</id>
    <properties>
        <env.resources.dir>src/test/resources</env.resources.dir>
        <extra.sources.dir>src/test/java</extra.sources.dir>
    </properties>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.8.1</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>org.springframework.test</artifactId>
            <scope>compile</scope>
        </dependency>
    </dependencies>
</profile>

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-dependency-plugin</artifactId>
  <executions>
    <execution>
      <id>copy-dependencies</id>
      <phase>compile</phase>
      <goals>
        <goal>copy-dependencies</goal>
      </goals>
      <configuration>
        <artifactSet>
          <includes>
        <include>com.example:foo</include>
          </includes>
        </artifactSet>
        <outputDirectory>target/dependencies</outputDirectory>
      </configuration>
    </execution>
  </executions>
</plugin>