fix: Attempt to fix execution directory clearing

Author: Alan Christie

tests/instance_launcher.py

@@ -60,12 +60,13 @@ def __init__(
         # Every launcher starts with an empty execution directory...
         print(f"Removing execution directory ({EXECUTION_DIRECTORY})")
         assert EXECUTION_DIRECTORY.startswith("tests/project-root")
-        for filename in os.listdir(EXECUTION_DIRECTORY):
-            file_path = os.path.join(EXECUTION_DIRECTORY, filename)
-            if os.path.isfile(file_path) or os.path.islink(file_path):
-                os.unlink(file_path)
-            elif os.path.isdir(file_path):
-                shutil.rmtree(file_path)
+        if os.path.isdir(EXECUTION_DIRECTORY):
+            for filename in os.listdir(EXECUTION_DIRECTORY):
+                file_path = os.path.join(EXECUTION_DIRECTORY, filename)
+                if os.path.isfile(file_path) or os.path.islink(file_path):
+                    os.unlink(file_path)
+                elif os.path.isdir(file_path):
+                    shutil.rmtree(file_path)
 
     def launch(self, launch_parameters: LaunchParameters) -> LaunchResult:
         assert launch_parameters