Check if the job is in a final state before attempting to ask the executor

to cancel it.

Author: hategan

src/psij/job.py

@@ -156,6 +156,10 @@ def cancel(self) -> None:
         """
         if not self.executor:
             raise SubmitException('Cannot cancel job: not bound to an executor.')
+        elif self.status.final:
+            # TODO: we probably need a different type of exception for this and the above case,
+            # TODO: but this is probably a spec issue
+            raise SubmitException('Cannot cancel a job in a final state')
         else:
             self.executor.cancel(self)