It seems that there is still some cleanup needed here. Britney still thinks this bug is a problem for testing migration.
I'm not 100% sure what is going on, but what I think needs to happen is that a removal request needs to be made to the ftpmasters to get rid of the golang-github-syndtr-goleveldb source package and associated binaries. Once this is done hopefully the version tracking stuff in the bts should become less confused and golang-goleveldb should be able to migrate to testing.
