maven找不到依赖plexus-compiler-eclipse

Question

<build>
    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.0</version>
            <dependencies>
                <dependency>
                    <groupId>org.codehaus.plexus</groupId>
                    <artifactId>plexus-compiler-eclipse</artifactId>
                    <version>2.6</version>
                </dependency>
            </dependencies>
            <configuration>
                <source>1.6</source>
                <target>1.6</target>
                <debug>true</debug>
                <optimize>true</optimize>
                <fork>true</fork>
                <compilerId>eclipse</compilerId>
            </configuration>
        </plugin>
    </plugins>
</build>

我想使用Eclipse编译器而不是javac，但是Maven说它无法找到依赖项。为什么？