ATM the ebuild does not check if you have any Cryptographic options set. The ebuild should instruct the user about this or recuire at least one of the usable ciphers to be selected. betelgeuse@pena /usr/src/linux/arch/i386 $ sudo cryptsetup -v --verify-passphrase luksFormat /dev/sdc2 WARNING! ======== This will overwrite data on /dev/sdc2 irrevocably. Are you sure? (Type uppercase yes): YES Enter LUKS passphrase: Verify passphrase: Failed to setup dm-crypt key mapping. Check kernel for support for the aes-cbc-essiv:sha256 cipher spec and verify that /dev/sdc2 contains at least 133 sectors. Failed to write to key storage. so for default luksFormat I needed the sha256 and aes_i586 kernel modules, but it should be able to use others I think with the -c option
Fixed in cvs, try -r3
