tools/file_import: make sure sys.path is always restored

artiq/tools.py

@@ -85,10 +85,10 @@ def file_import(filename, prefix="file_import_"):
 
     path = os.path.dirname(os.path.realpath(filename))
     sys.path.insert(0, path)
-
+    try:
         loader = importlib.machinery.SourceFileLoader(modname, filename)
         module = loader.load_module()
-
+    finally:
         sys.path.remove(path)
 
     return module