Comment 1 for bug 1481133

This is caused by this helpful footgun

// updateDistroInfo updates seriesVersions from /usr/share/distro-info/ubuntu.csv if possible..
func updateDistroInfo() error {
        // We need to find the series version eg 12.04 from the series eg precise. Use the information found in
        // /usr/share/distro-info/ubuntu.csv provided by distro-info-data package.
        f, err := os.Open(distroInfo)
        if err != nil {
                // On non-Ubuntu systems this file won't exist but that's expected.
                return nil
        }
        defer f.Close()
        bufRdr := bufio.NewReader(f)

If /usr/share/distro-info/ubuntu.csv is missing, then we quietly pretend like there are NO UBUNTU SERIES EVER!!!