[arch-releng] ISO 2014.11.01: installing packages may cause system failure

As of ISO 2014.11.01 attempts to install packages within the live system itself can cause complete system failure, apparently due to problems affecting device mapper. The problem is a regression that can't be seen with ISO 2014.10.01. It doesn't always appear and I couldn't find out the exact conditions. But it seems the number / volume of packages that are about to be installed has to exceed some kind of threshold. Also, it doesn't affect running pacstrap the usual way. Attaching journalctl output from a KVM/QEMU instance (behaviour is the same booting "bare metal", though). Regards.