I have this issue where datastoreInfo.mtime is nil for some of my datastores. I would expect that it can never be nil. This is all the more curious that datastore.mtime is never nil for the same datastore. This makes the mtime attribute unrealiable to use.
I have had this issue for several months now but never got round to reporting it/examining it deeply.
Caram
(main)> store
=> #<DBDatastore:0x111ea5680>
(main)> store.mtime
=> 2015-02-14 22:20:08 +0100
(main)> store.manager.listDatastoreInfo(nil).select{ |id, info| info.mtime == nil }.values.first.mtime
=> nil
iOS 8.1.3
XCode 6.1
SDK 3.1.2