message: drake.cxx: don't run otool on non ELF
diff: @@ -2166,6 +2166,7 @@ class PatchAndInstall(drake.Install):
  return False
  if os.path.islink(str(self.target.path())):
  return True
  - if sys.platform == 'darwin':
  + if sys.platform == 'darwin' \
  + and isinstance(self.target, (DynLib, Executable)):
  self.get_deps_fix_rpaths(self.target.path())
  return True
  