Public bug reported: When I updated from 18.04 to 20.04 with do-release-upgrade, I noticed that the cups package prerm script would hang forever. After I hit ctrl-C, it was fairly messy to fix the system back together.
When I traced this, I found that `which` in the prerm script (and not just cups but potentially all of them?) resolved to /usr/local/bin/which from my $PATH, which was from the npm `which` package. I don't really understand how even `npm which` could hang, but it did somehow. Everything worked again after I deleted npm `which`. The lesson here seems to be that do-release-upgrade should restrict $PATH so that these kinds of problems can't happen. This is a possible problem for apt in general, but it's more problematic for do-release-update since it could not be rolled back in this case. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: ubuntu-release-upgrader-core 1:20.04.28 ProcVersionSignature: Ubuntu 5.4.0-51.56-generic 5.4.65 Uname: Linux 5.4.0-51-generic x86_64 NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair nvidia_modeset nvidia ApportVersion: 2.20.11-0ubuntu27.9 Architecture: amd64 CasperMD5CheckResult: skip CrashDB: ubuntu Date: Mon Oct 19 10:12:55 2020 InstallationDate: Installed on 2018-11-13 (706 days ago) InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725) PackageArchitecture: all SourcePackage: ubuntu-release-upgrader Symptom: release-upgrade UpgradeStatus: Upgraded to focal on 2020-10-17 (1 days ago) ** Affects: ubuntu-release-upgrader (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug dist-upgrade focal third-party-packages -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1900390 Title: do-release-update hangs from use of user $PATH (specifically 'npm which') To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1900390/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs