This bug affects encrypting a swap *file* via ecryptfs (so affecting also ubiquity when using ecrypfs to encrypt home and swapfile), and the patch I made is for an ecryptfs-utils script (even if also ubiquity may need to be patched, too, see above my comment #6)
bug #1668535 instead concerns encryption of a swap *partition*, and the patch you find there is for systemd
It seems that they are two different things.
This bug affects encrypting a swap *file* via ecryptfs (so affecting also ubiquity when using ecrypfs to encrypt home and swapfile), and the patch I made is for an ecryptfs-utils script (even if also ubiquity may need to be patched, too, see above my comment #6)
bug #1668535 instead concerns encryption of a swap *partition*, and the patch you find there is for systemd