The code cannot be compiled:

storage/localstore/mode_put_test.go:325:19: cannot use func literal (type func(chunk.Address) bool) as type func([]byte) bool in field value

@nolash the issue is as follows:
In the old syncer an upstream peer would tell the downstream peer on which bins to ask for chunks on (subscriptions). this would guarantee, for example, that the upstream peer would establish subscriptions on bins within depth, although that upstream peer might have the downstream peer outside of it's saturation depth. this would also always guarantee that all chunks will get synced from the downstream peer at some point or another (since subscriptions were established according to the downstream peer's perspective).

in the new stream this is not the case. upstream peers establish streams according to their own kademlia and regardless of the downstream peer's connectivity. while this is more resilient implementation (and less attack prone), it did not in its naive implementation cater for the fact that the downstream peer might be the closest node to certain chunks. the connectivity pattern that was manifesting was that the downstream peer appeared outside of saturation depth of other nodes, thus syncing of certain chunks was not bound to happen (since the downstream peer was the closest one and the upstream peers all had not been subscribed to that node's higher bins since it was outside of their depth). this therefore manifested in a localstore leak since some chunks were never Set therefore never added to gcIndex therefore never deleted.

@janos I think I understand more or less. Thanks.

Still not sure about the "what is anonmous content syncing on light nodes" though :)