Hello and thanks for this bug report. By reading the bug description it looks like there is an issue in your sshd_config:
SSHDConfig: Error: command ['/usr/sbin/sshd', '-T'] failed with exit code 255: /etc/ssh/sshd_config line 15: Badly formatted port number. If sshd was working before it may be that the service wasn't restarted after the breaking config change. The upgrade triggered a restart and thus the failure. I'm setting this bug report as Incomplete for now. Should you think that this is actually a bug in Ubuntu and not a local configuration issue please comment back providing your reasoning and a sshd_config line that reproduces the issue in a clean Ubuntu system. On the other hand should you find out this is actually a local configuration issue please set the status of this bug report to Invalid. Thanks! ** Changed in: openssh (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to openssh in Ubuntu. https://bugs.launchpad.net/bugs/1939940 Title: package openssh-server 1:8.2p1-4ubuntu0.3 failed to install/upgrade: installed openssh-server package post-installation script subprocess returned error exit status 1 Status in openssh package in Ubuntu: Incomplete Bug description: this happened during an update ProblemType: Package DistroRelease: Ubuntu 20.04 Package: openssh-server 1:8.2p1-4ubuntu0.3 ProcVersionSignature: Ubuntu 5.11.0-25.27~20.04.1-generic 5.11.22 Uname: Linux 5.11.0-25-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.18 Architecture: amd64 CasperMD5CheckResult: skip Date: Sat Aug 14 08:13:05 2021 ErrorMessage: installed openssh-server package post-installation script subprocess returned error exit status 1 InstallationDate: Installed on 2020-11-11 (275 days ago) InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731) Python3Details: /usr/bin/python3.8, Python 3.8.10, python3-minimal, 3.8.2-0ubuntu2 PythonDetails: N/A RelatedPackageVersions: dpkg 1.19.7ubuntu3 apt 2.0.6 SSHDConfig: Error: command ['/usr/sbin/sshd', '-T'] failed with exit code 255: /etc/ssh/sshd_config line 15: Badly formatted port number. SourcePackage: openssh Title: package openssh-server 1:8.2p1-4ubuntu0.3 failed to install/upgrade: installed openssh-server package post-installation script subprocess returned error exit status 1 UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/1939940/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp