Bastien, which version of mkswap are you using?I tried the following command with no problems parsing the empty UUID string.
$ sudo mkswap -L "" -U "" /dev/sdd3 Setting up swapspace version 1, size = 57569 kB LABEL=, UUID=f8b00408-e87e-bcbf-7c8b-0408a42eedb7 $ $ mkswap --version mkswap (util-linux-ng 2.13.1) $ -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org