我有Ubuntu 19.10，正在尝试升级到20.04.1。我遵循了各种教程，但最后我总是面临着同样的问题。当我跑步
sudo do-release-upgrade
日志为：
Checking for a new Ubuntu release
Your Ubuntu release is not supported anymore.
For upgrade information, please visit:
http://www.ubuntu.com/releaseendoflife
如果我跑步
sudo do-release-upgrade -d
日志为：
Checking for a new Ubuntu release
Upgrades to the development release are only
available from the latest supported release.
我还尝试了从Software Updater升级，当我尝试升级时，该窗口便消失了。顺便说一下，我有1GB的可用内存，我不知道这可能是问题所在。
P.S：lsb_release -a的输出：
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 19.10
Release: 19.10
Codename: eoan