jhonen@jhonen-DellLaptop:~$ sudo do-release-upgrade --devel-release
Checking for a new ubuntu release
Done Upgrade tool signature
Done Upgrade tool
Done downloading            
extracting '/tmp/tmphSLDZD/hardy.tar.gz'
authenticate '/tmp/tmphSLDZD/hardy.tar.gz' against '/tmp/tmphSLDZD/hardy.tar.gz.gpg' 
exception from gpg: GnuPG exited non-zero, with code 131072
Debug information: 

gpg: WARNING: unsafe permissions on homedir `/tmp/tmphSLDZD'
secmem usage: 1408/1408 bytes in 2/2 blocks of pool 1408/32768

gpg: Signature made Fri 21 Mar 2008 11:39:57 AM CDT using DSA key ID 437D05B5
gpg: fatal: error writing to `/tmp/tmphSLDZD/.#lk0x8123310.jhonen-DellLaptop.7055': No space left on device

Authentication failed
Authenticating the upgrade failed. There may be a problem with the network or with the server. 
jhonen@jhonen-DellLaptop:~$