Alexandre Takacs wrote:(that's me canceling after 7h)
You have a lot more patience than I do.
The "Locating changes" phase is playing back the filesystem event log to determine what folders contain changes. QRecall requests a playback of changes and then waits to receive them. This should take, at most, a minute, and usually only takes a few seconds.
I suspect something is wrong and OS X simply failed, or started and never finished, sending the events and QRecall was left waiting forever.
This might be a transient problem. First, try restarting your system and try again.
If it happens again, you might consider resetting your filesystem history on Macintosh HD. There's an official API for doing this programmatically, but I don't know of any utilities you can download that will do that for you.
The "unsupported" method is simply wipe the filesystem history for your volume and restart your system. Open up a Terminal window and execute the following command:
sudo rm /.fseventsd/*
The command will prompt you for your admin password. After it finishes, immediately restart your system.
Be very careful about entering this command exactly as shown. The sudo rm command can do some serious damage if incorrectly used. One of those should fix your problem. If it doesn't, I suspect a deeper issue with OS X.