Ubuntu 16.04 LTS – unmet dependencies prevent apt install and upgrade – 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 reports unmet dependencies and refuses package changes.

Environment & Reproduction

Mixed repositories or partial upgrades on Ubuntu 16.04 systems.

Root Cause Analysis

Incompatible package versions produce an unsatisfied dependency chain.

Quick Triage

Run apt-cache policy and apt -f install to inspect resolver output.

Step-by-Step Diagnosis

Map conflicting package versions and identify the foreign repository source.

Solution – Primary Fix

Pin compatible versions, remove conflicting sources, then complete install.

Solution – Alternative Approaches

Use aptitude interactive resolver when apt cannot automatically converge.

Verification & Acceptance Criteria

apt upgrade resolves all dependencies with no held broken packages.

Rollback Plan

Revert package pins and restore previous repository list backup.

Prevention & Hardening

Avoid mixing unsupported PPAs and enforce repository governance.

Automate patch management and compliance across your fleet with our DevOps services.

Related Errors & Cross-Refs

Held packages and obsolete package candidates are common companions.

Related tutorial: View the step-by-step tutorial for Ubuntu 16.04 LTS.

View all Ubuntu 16.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu package dependency management and pinning reference.