I just picked up a new rMBP on Thursday and I thought I would report on an interesting issue that cropped up as a result of (I believe) using Migration Assistant to move my files and settings over from my old 2010 MBP. I connected the machines directly together via Firewire, and I initiated the Migration after the initial setup of the new machine. I opted to transfer everything. My new Mac works great, and everything seems to be in place where I left it on the old Mac (even custom EQ settings from iTunes carried over). The issues began when I went to backup my new machine to my old Time Machine backups. I know this is typically possible; the new Mac can inherit the backups of an older Mac, and that's exactly what I planned on doing. I figured this wouldn't be a problem since Migration Assistant practically perfectly cloned the data from the old drive, but Time Machine kept failing. In delving into the system.log, I decided to investigate the files that TM was failing on (Error: -36), as I had read that permissions could cause major issues like the one that I was having. The file paths didn't appear to make any sense, though, as failed files were living in paths like: /Applications/Utilities/Applications/Adobe/... which makes no sense, as my Adobe applications are stored in /Applications, and I shouldn't have had another Applications folder inside of /Utilities. It appears that Migration Assistant created a couple of loops in my file system, and I had found the first one in the Utilities folder. Inside, there was an entire copy of the Applications folder, along with its own Utilities folder, and this nested Utilities folder had a symlink to the nested applications folder. I checked with my old machine, and this loop didn't exist there. So I deleted it and went on my way and attempted to restart the backup, and it failed again. This time, there was another loop in /Library/Frameworks, with a second copy of /Frameworks inside of the first, with a symlink in the nested copy. I was unable to find anything with some searches of anyone else having had this issue. I was about to give up and start my TM backups fresh rather than trying to inherit the old backups, but I've decided that I should probably keep letting it try to backup and fail so that I can clean out any other loops that may have been created. I'll post back here with my findings, but I'm curious if anyone else has seen a similar issue. If nothing else, this can exist for anyone else that may run into problems in the future.