compiler-rt/test/tsan/Darwin/lit.local.cfg.py

def getRoot(config):
  if not config.parent:
    return config
  return getRoot(config.parent)

root = getRoot(config)

if root.host_os not in ['Darwin']:
  config.unsupported = True

config.environment['TSAN_OPTIONS'] += ':ignore_noninstrumented_modules=1'