Thanks for the reports, I’ve added further debug output based on these, as unfortunately they were not enough to pinpoint the exact problem.
Please update to v2.0-rc.29 and send me output from this build, when the problem happens again.
My theory is that this is the OS trying to obtain a lock which is already locked, and there is then a ~10 seconds timeout on this lock, which explains why the delay is always so close to 10 seconds (and so extremely long, compared to normal delays arising from loading data, swapping out memory, etc.).