在/var/log/dist-upgrade/main.log
（先前）
2023-07-31 12:38:07,292 ERROR NoDistroTemplateException raised: Error: could not find a distribution template for Ubuntu/focal
Traceback (most recent call last):
File "/tmp/ubuntu-release-upgrader-2ka77vmt/DistUpgrade/DistUpgradeController.py", line 508, in rewriteSourcesList
distro.get_sources(self.sources)
File "/tmp/ubuntu-release-upgrader-2ka77vmt/DistUpgrade/distro.py", line 91, in get_sources
raise NoDistroTemplateException(
DistUpgrade.distro.NoDistroTemplateException: Error: could not find a distribution template for Ubuntu/focal
（之后）
2023-07-31 12:40:03,598 ERROR failed to mark 'kubuntu-desktop' for install (E:Unable to correct problems, you have held broken packages.)
2023-07-31 12:40:03,694 DEBUG denylist expr 'update-manager$' matches 'update-manager'
2023-07-31 12:40:03,694 DEBUG The package 'update-manager' is marked for removal but it's in the removal deny list
2023-07-31 12:40:03,722 ERROR Dist-upgrade failed: 'The package 'update-manager' is marked for removal but it is in the removal deny list.'
2023-07-31 12:40:03,735 DEBUG abort called
（完整日志文件） https://gandsnut.net/temp/apt.log https://gandsnut.net/temp/main.log
尝试过 apt-get update 和 upgrade、apt autoremove，运行“sudo do-release-upgrade”时，发布升级过程失败
不确定如何前进。谢谢...