Public bug reported: Landscape-package-reporter resp. `apt.systemd.daily` trigger a `apt-get update`. As my company uses a VPN and some of my APT sources are hosted inside the VPN, DNS resolution of those hosts sometimes fail, especially after suspend-to-disk/ram after which the VPN does no longer work until I re-login.
If `apt-get update` then runs it looks like the first DNS lookup fails and APT schedules the repository for retry. After 2 more failures `apt- transport-http` gives up and stops trying, but `apt-get` (the parent process) still sees one outstanding request and waits forever. With 'Debug::pkgAcquire "true"' and 'Debug::phgAcquire::Worker "true"' and a wrapper around '/usr/bin/apt-get' I was finally able to capture a log-output showing the issue: -> https:600 URI Acquire URI: https://packages.XXX.de/XXX-core/ubuntu/dists/noble/InRelease Filename: /var/lib/apt/lists/partial/packages.XXX.de_XXX-core_ubuntu_dists_noble_InRelease Target-Type: index Target-Release: noble Target-Repo-URI: https://packages.XXX.de/XXX-core/ubuntu/ Target-Base-URI: https://packages.XXX.de/XXX-core/ubuntu/dists/noble/ Target-Site: https://packages.XXX.de/XXX-core/ubuntu Index-File: true Maximum-Size: 10000000 Last-Modified: Tue, 09 Dec 2025 07:41:33 GMT Fail-Ignore: true Signed-By: … <- https:102 Status Message: Connecting tot packages.XXX.de URI: https://packages.XXX.de/XXX-core/ubuntu/dists/noble/InRelease <- https:400 URI Failure Transient-Failure: true FailReason: ResolveFailure Message: Could not resolve 'packages.XXX.de' URI: https://packages.XXX.de/XXX-core/ubuntu/dists/noble/InRelease Landscape resp. APT then hangs there forever until I do a `sudo pkill apt-get`. No updates – including any security updates – are installed until then. I have found 2 suspect location in the APT source code: 1. https://salsa.debian.org/apt-team/apt/-/blob/main/apt-pkg/acquire-item.cc?ref_type=heads#L915-921 puts the worker into an idle state to wait for the next retry. Maybe the worker should exit here instead if the last retry failed? 2. https://salsa.debian.org/apt-team/apt/-/blob/main/apt-pkg/acquire-worker.cc?ref_type=heads#L686-765 handles the retries. Is the `Owner->Retries != 0` there wrong or is a fall-through in case of an error missing, when all retries failed? I have been unable to force this bug by disabling the VPN and running `apt-get update` manually, so one important condition might be missing from my report. Any advise on how to continue debugging here is also appreciated. ProblemType: Bug DistroRelease: Ubuntu 24.04 Package: ubuntu-release-upgrader-core 1:24.04.27 ProcVersionSignature: Ubuntu 6.8.0-90.91-generic 6.8.12 Uname: Linux 6.8.0-90-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.28.1-0ubuntu3.8 Architecture: amd64 CasperMD5CheckResult: pass CrashDB: ubuntu CurrentDesktop: ubuntu:GNOME Date: Fri Jan 30 13:08:08 2026 InstallationDate: Installed on 2025-01-31 (364 days ago) InstallationMedia: Ubuntu 22.04.5 LTS "Jammy Jellyfish" - Release amd64 (20240911) PackageArchitecture: all SourcePackage: ubuntu-release-upgrader Symptom: dist-upgrade UpgradeStatus: No upgrade log present (probably fresh install) VarLogDistupgradeTermlog: ** Affects: ubuntu-release-upgrader (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug dist-upgrade noble -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2139418 Title: apt-get update stalls infinitely if DNS resolution fails To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/2139418/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
