To use in a waf project with git, go:

$ git submodule add git://github.com/ilkka/waftools.git tasks

and in your wscript, add:

...
import os
from tasks import <whatever>
...
def configure(conf):
  conf.check_tool('scala', tooldir=os.getcwd()+'/tasks')
...
def build(bld):
  b = bld(features='scala', source='whatever.scala')
...