The runtime executes the build script, outputing to the system log and throwing any unhandled exceptions out.
The operator specifies the identifier of a resource which will be used as the build file. Ant uses an XML format which is documented here. Ant is a filesystem based tool and does not work directly with the ROC address space, so if a file: identifier is specified as the operator that is used directly. If not the resources is SINKed to temporary file and Ant is executed with that file. In that case the build file must not assume any specific location as often build files contain paths relative the location of the build file.
Ant defaults to building the default build target and all it's dependencies. However it is possible to specify specific targets to build in a similar way to the command line by specifying one or more target arguments. These are SOURCEd as strings.
Ant takes an optional XML configuration resource.