When using preupgrade to upgrade an existing Fedora 14 installation to Fedora 15, the following two errors were encountered: Failed to fetch release info No groups available in any repository The box sits on a network behind a proxy out to the web. The resolution was to make sure that environment variables http_proxy and https_proxy are set: [sourcecode language=“bash”] export http_proxy=http://user:password@proxyserver:port export https_proxy=http://user:password@proxyserver:port [/sourcecode] Make sure you do this from the user from which you run preupgrade.