workunits_via_params.py

@rule(Logger, [Workunit])
def logger(workunit):
  # Maybe we don't need both `Logger` and `Workunit`?
  ..

@rule(Classpath, [Logger, Target])
def compile_some_stuff(logger, target):
  ..

@console_rule(Compile, [Specs])
def compile(specs):
  workunit = Workunit('compile')
  targets = ..
  # Assuming syntax from https://github.com/pantsbuild/pants/issues/7490:
  root_classpaths = [yield Get(Classpath, {Target: t, Workunit: w}) for t in targets]
  ..