UnboundLocalError: local variable 'index' referenced before assignment

[JPugetGil]

When I use the feature persistence I am getting this error message :

File "/usr/src/app/./quit/run.py", line 20, in <module>
2023-05-05 14:44:25     application = create_app(args)
2023-05-05 14:44:25   File "/usr/src/app/./quit/web/app.py", line 110, in create_app
2023-05-05 14:44:25     register_app(app, arguments)
2023-05-05 14:44:25   File "/usr/src/app/./quit/web/app.py", line 138, in register_app
2023-05-05 14:44:25     quit.syncAll()
2023-05-05 14:44:25   File "/usr/src/app/./quit/core.py", line 173, in syncAll
2023-05-05 14:44:25     self.syncSingle(commit)
2023-05-05 14:44:25   File "/usr/src/app/./quit/core.py", line 177, in syncSingle
2023-05-05 14:44:25     self.changeset(commit)
2023-05-05 14:44:25   File "/usr/src/app/./quit/core.py", line 370, in changeset
2023-05-05 14:44:25     prev_uri = QUIT["graph-{}-{}".format(prev.oid, index)]
2023-05-05 14:44:25 UnboundLocalError: local variable 'index' referenced before assignment

This is the docker command I have executed :
docker run -d -it --name quitstore2 -p 8081:8080 -v $PWD:/data aksw/quitstore uwsgi --http 0.0.0.0:8080 -w quit.run -b 40960 --pyargv "-vv -t /data -f provenance -f persistence"