Misc cleanup

src/render_queue.py

@@ -65,10 +65,12 @@ class RenderQueue:
 
     @classmethod
     def job_with_id(cls, job_id, none_ok=False):
-        found_job = next((x for x in cls.all_jobs() if x.id == job_id), None)
-        if not found_job and not none_ok:
-            raise JobNotFoundError(job_id)
-        return found_job
+        for job in cls.all_jobs():
+            if job.id == job_id:
+                return job
+        if not none_ok:
+            raise JobNotFoundError(f"Cannot find job with id: {job_id}")
+        return None
 
     @classmethod
     def clear_history(cls):