Restore this for the testing

packages/py-spinnfrontendcommon/package.py

@@ -8,6 +8,7 @@ from spack.store import find
 from llnl.util import tty
 from os import makedirs
 from urllib.request import urlretrieve
+import os
 
 
 _JAR_URL = "https://github.com/SpiNNakerManchester/JavaSpiNNaker/releases/download/7.0.0/spinnaker-exe.jar"