Comment 0 for bug 1838329

On some systems, cryptsetup-based encrypted swap partitions cause systemd to get stuck at boot. This is a timing-sensitive Heisenbug, so the rate of occurrence varies from one system to another. Some hardware will not experience the issue at all, others will only occasionally experience the issue, and then there are the unlucky who are unable to boot at all, no matter how many times they restart.

The workaround is for the cryptsetup-generator to generate cryptswap service entries that call `udevadm trigger` after `mkswap`. This will ensure that the udev event is triggered, so that systemd is notified that the encrypt swap partition is ready to activate. This patch has already been submitted upstream to systemd, but it was not accepted because it is a workaround for the side effect of systemd not seeing the udev event upon creating the swap partition.