编译subfloor.xml时Pentaho Kettle构建失败

Question

我正在尝试使用

编译pentaho-kettle

ant dist

当我遇到一些编译错误时，按照github repository https://github.com/pentaho/pentaho-kettle的指示执行

命令：

compile.compile:
[javac] /home/dimasta/Documents/pentaho-kettle/core/build-res/subfloor.xml:1560: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds
[javac] Compiling 352 source files to /home/dimasta/Documents/pentaho-kettle/core/bin/classes
[javac] javac: invalid target release: 8
[javac] Usage: javac <options> <source files>
[javac] use -help for a list of possible options

BUILD FAILED
/home/dimasta/Documents/pentaho-kettle/build.xml:123: The following error occurred while executing this line:
/home/dimasta/Documents/pentaho-kettle/build.xml:128: The following error occurred while executing this line:
/home/dimasta/Documents/pentaho-kettle/core/build-res/subfloor.xml:1560: Compile failed; see the compiler error output for details.

Total time: 21 seconds

如何解决这个问题？

P.S。我是pentaho-kettle的新手，所以请以最简单的方式解释

感谢。