Upgrading hangs when NFS mounts are present

[Julian Edwards]

When upgrading to 24.04 today, the process stalled when it got to os-prober checks for other installed OSes.

As far as I can determine, this was because the network connection was completely destroyed during upgrade leaving the machine without connectivity, and when os-prober runs it erroneously attempts to look inside NFS mounts. Since there is no connectivity, it will apparently stall forever on this while the kernel logs a lot of errors to syslog.

ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: ubuntu-release-upgrader-core 1:24.04.18
ProcVersionSignature: Ubuntu 6.8.0-31.31-generic 6.8.1
Uname: Linux 6.8.0-31-generic x86_64
ApportVersion: 2.28.1-0ubuntu3
Architecture: amd64
CasperMD5CheckResult: unknown
CrashDB: ubuntu
CurrentDesktop: KDE
Date: Sat May 25 16:31:34 2024
InstallationDate: Installed on 2019-07-04 (1787 days ago)
InstallationMedia: Kubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
Symptom: release-upgrade
UpgradeStatus: Upgraded to noble on 2024-05-25 (0 days ago)
VarLogDistupgradeXorgFixuplog:
 INFO:root:/usr/bin/do-release-upgrade running
 INFO:root:No xorg.conf, exiting