17:37UTC:root@bard:~# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.5 LTS
Release: 18.04
Codename: bionic
17:38UTC:root@bard:~# do-release-upgrade
Checking for a new Ubuntu release
There is no development version of an LTS available.
To upgrade to the latest non-LTS develoment release
set Prompt=normal in /etc/update-manager/release-upgrades.`
为什么我的升级管理器说没有可用的 LTS“开发”版本？
17:41UTC:root@bard:~# cat /etc/update-manager/release-upgrades
# Default behavior for the release upgrader.
[DEFAULT]
# Default prompting behavior, valid options:
#
# never - Never check for, or allow upgrading to, a new release.
# normal - Check to see if a new release is available. If more than one new
# release is found, the release upgrader will attempt to upgrade to
# the supported release that immediately succeeds the
# currently-running release.
# lts - Check to see if a new LTS release is available. The upgrader
# will attempt to upgrade to the first LTS release available after
# the currently-running one. Note that if this option is used and
# the currently-running release is not itself an LTS release the
# upgrader will assume prompt was meant to be normal.
Prompt=lts
该系统有 [在我看来] 一个通用/etc/apt/sources.list文件。指向各种ubuntu.comBionic 存储库。
？？
答案1
哦！特殊情况：Canonical 阻止 Focal 修复严重错误。“关键”版本 (20.04.01) 已发布，但尚未“发布”用于从 18.04LTS 升级
https://discourse.ubuntu.com/t/focal-fossa-20-04-1-lts-point-release-status-tracking/17604