Groovy project won't build in GGTS

Groovy project won't build in GGTS

I have some Groovy code which will from fine from the command line, but
when I try to use Springsource's GGTS fails:
Caught: java.lang.NoClassDefFoundError: org/apache/commons/cli/ParseException
java.lang.NoClassDefFoundError: org/apache/commons/cli/ParseException
at empyrean.Empyrean.run(Empyrean.groovy:20)
Caused by: java.lang.ClassNotFoundException:
org.apache.commons.cli.ParseException
... 1 more
I know this is because I have not got paths or something similar set
correctly in GGTS but I cannot work out how to fix this (I used to use STS
without a problem, this is the first time I have tried GGTS)
The non-compiling code is this:
def empyreanParse = empyreanCli.parse(args)
if (empyreanParse.u || args.size() == 0)
empyreanCli.usage()
else {
def engine = new EmpyreanEngine()
if (empyreanParse.d)
engine.debug = true
if (empyreanParse.f)
engine.process(binsicParse.f)
else
engine.process(args[args.size() - 1])
}
Which, as I say, runs fine from the command line...