ant warning: “’includeantruntime’ was not set”

following warning:
warning: 'includeantruntime' was not set,
defaulting to build.sysclasspath=last; set to false for repeatable builds

presetdef is a good option. Especially if one is working on a project with many build.xml

To use presetdef, add these lines in your top-level build.xml file:
<presetdef name="javac">
<javac includeantruntime="false" />
</presetdef>