```
root@install1002:~# reprepro ls stretch-wikimedia
Error: packages database contains unused 'trusty-wikimedia|main|amd64' database.
This usually means you removed some component, architecture or even
a whole distribution from conf/distributions.
In that case you most likely want to call reprepro clearvanished to get rid
of the databases belonging to those removed parts.
(Another reason to get this error is using conf/ and db/ directories
 belonging to different reprepro repositories).
To ignore use --ignore=undefinedtarget.
There have been errors!
root@install1002:~# 
```