For those having trouble with OTA, try another mirror. chrox's master is hosted very, very far away from most of us, and even on a dedicated box with awesome peerings and bandwidth, it's nearly like I'm back on dialup

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If you can, try to monitor what's happening over a shell. It should first build a tarball of the current install (which might take ~30s of heavy I/O), and then start downloading the new version (hopefully, in the form of a delta, so, not much data needed).
AFAICT, there's no feedback in case of error, which might be a tad confusing.