Debian 9 – full-upgrade blocked by held packages – Fix & Prevention

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

`apt full-upgrade` fails with unmet dependencies and blocked package transitions.

Environment & Reproduction

Common after manual pinning or partial upgrades.

cat /etc/debian_version
sudo apt-mark showhold
sudo apt update
sudo apt full-upgrade

Root Cause Analysis

Held packages and pin priorities prevent resolver from completing required upgrades.

Quick Triage

Enumerate holds, pins, and broken package state.

sudo apt-mark showhold
grep -RIn 'Pin:' /etc/apt/preferences /etc/apt/preferences.d 2>/dev/null
sudo apt -f install -y

Step-by-Step Diagnosis

Use resolver debug output to identify blockers.

sudo apt-get -o Debug::pkgProblemResolver=yes dist-upgrade -s
sudo dpkg --audit
sudo tail -n 120 /var/log/apt/term.log

Solution – Primary Fix

Remove unnecessary holds and normalize package state.

for p in $(apt-mark showhold); do sudo apt-mark unhold $p; done
sudo dpkg --configure -a
sudo apt -f install -y
sudo apt full-upgrade -y

Solution – Alternative Approaches

Disable third-party repositories temporarily to isolate conflicts.

sudo mkdir -p /var/tmp/apt-sources-backup
sudo cp -a /etc/apt/sources.list.d /var/tmp/apt-sources-backup/
sudo sed -i 's/^deb/#deb/g' /etc/apt/sources.list.d/*.list
sudo apt update

Verification & Acceptance Criteria

No holds remain and full-upgrade simulation succeeds.

sudo apt-mark showhold
sudo apt-get check
sudo apt full-upgrade -s

Rollback Plan

Reapply required holds after compatibility validation.

sudo apt-mark hold 
sudo cp -a /var/tmp/apt-sources-backup/sources.list.d/* /etc/apt/sources.list.d/
sudo apt update

Prevention & Hardening

Track holds centrally and review before maintenance windows.

apt-mark showhold > /var/tmp/held-packages.txt
apt-cache policy | head -n 120

Related Errors & Cross-Refs

Related to obsolete repositories, stale pin files, and partial upgrades.

Related tutorial: View the step-by-step tutorial for Debian 9.

View all Debian 9 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Debian apt policy and pinning guidance.