You are atempting to upgrade to a version of Trisquel that is no longer supported. Since we do only keep upgrade packages for decomissioned releases for a while, this upgrade may fail. Try the sandbox method first (by running update-manager -s) or ask in our forums, lists or irc channels if you are unsure about this procedure.
Even if the required upgrade packages for etiona are still available, to get a currently supported release you would need to upgrade at least once more after this procedure ends, so we recommend you to do a clean install using the latest LTS or STS edition.
If you would like to help shape Trisquel, take a look at the list of ways you can participate at
http://trisquel.info/en/wiki/how-help
Your comments, bug reports, patches and suggestions will help ensure that our next release is the best release of Trisquel ever. If you feel that you have found a bug please send it to us via
http://trisquel.info/project/issues
If you have a question, or if you think you may have found a bug but aren't sure, first try asking on the #trisquel IRC channel on Freenode, on the Trisquel Users mailing list, or on the Trisquel forums:
http://listas.trisquel.info/ http://trisquel.info/forum
You can find out more about Trisquel on our website, IRC channel and wiki. If you're new to Trisquel, please visit:
http://trisquel.info
To sign up for future Trisquel announcements, please subscribe to Trisquel's very low volume announcement list at:
http://listas.trisquel.info/mailman/listinfo/trisquel-announce