Maven Error: Too many files with unapproved license

错误信息

在使用如下maven命令编译Flink源码时，

mvn clean install -DskipTests

出现错误：

[ERROR] Failed to execute goal org.apache.rat:apache-rat-plugin:0.12:check (default) on project flink-parent: Too many files with unapproved license: 2 See RAT report in: D:\Flink\repositories\flink\target\rat.txt -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
[ERROR]
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR]   mvn  -rf :flink-parent

错误解决

在mvn命令中加上-Drat.skip=true进行编译即可