Undefined manifest tag type: hashstates

Error when doing a dry-run using:

./bin/docker-distribution-pruner -config /var/opt/gitlab/registry/config.yml -parallel-repository-walk -parallel-blob-walk -debug

...
...
INFO[0089] TAG: xx/yy : 89178cd : is using: 89fa27c6b35663e06f21d8cee0f8f61147b467c06a71691348a9b862dc19ea1d 
INFO[0089] TAG: xx/yy : 93d4395 : is using: 1f2387108833f0151af4896dfffde239d635309dd4bcd6a1190e1429bf68c2e5 
INFO[0089] TAG: xx/yy : ed83786 : is using: 860a8a5c66ba53ff0b0794a2def94069c24440e8079ab241a9c1bc39d36fb4f8 
INFO[0089] TAG: xx/yy : latest : is using: cd59b851404dd8ed29275f919cf87f1f350409e07ef40b55953c7673113f636a 
INFO[0090] TAG: xx/zz : latest : is using: 91e26609628d00fd1cc2e36fdb46da6dec5c8e1614cece28a7e60e6aebda45d0 
INFO[0092] TAG: xx/aa : latest : is using: 5245544fc5cf5a6da9a74d23282fd4ac1012c986699723e7c87c2f37e206e5b6 
FATA[0092] undefined manifest tag type: hashstates  
(Exits)

Been using the registry since it became a feature in GitLab. Not too sure where to go from here.