[I can't find the original message, so sorry about incorrect threading]
This bug is another symptom of issues which make it hard to run Fedora in "small" systems with "only" 1GB of RAM.
Another is that LUKS filesystem decryption uses a deliberately "memory-hard" algorithm called Argon2 which requires loads of RAM and sometimes has problems running on a machine with 1GB and no swap.
Libguestfs is affected here because our appliance has limited RAM. So when we operate on disk images eg through virt-customize, some features like --install packages and fs decryption can fail unnecessarily.
I do think we should block the Fedora release if basic features don't work on such machines. A machine with 1GB of RAM should even be able to run a full system with GUI, and certainly should be usable from the command line. (Insert statement here about how back in the day I ran multiuser Minix on a PC with 640K of RAM and a steady hand ...)
Rich.