📖 ~1 min read
Table of contents
Symptom & Impact
Security updates cannot be applied due to unmet dependency chains.
Environment & Reproduction
Common after mixed repositories, partial upgrades, or held packages.
Root Cause Analysis
Package graph includes version conflicts that apt cannot satisfy automatically.
Quick Triage
Identify held packages and conflicting repository priorities.
Step-by-Step Diagnosis
Use apt-cache policy and dependency checks to map conflict edges.

Solution – Primary Fix
Unhold or pin correctly, repair dependencies, and complete controlled upgrade.
Still having issues? Our IT Solutions & Services team can diagnose and resolve this for you. Get in touch for a free consultation.

Solution – Alternative Approaches
Purge obsolete packages and migrate to clean repository baselines.
Verification & Acceptance Criteria
apt upgrade completes and package manager reports clean dependency state.
Rollback Plan
Reinstall previous package versions from snapshot if breakage occurs.
Prevention & Hardening
Limit repository sprawl and enforce package pinning policy.
Related Errors & Cross-Refs
Often appears with held packages and interrupted dist-upgrade attempts.
Related tutorial: View the step-by-step tutorial for Ubuntu 14.04 LTS.
View all Ubuntu 14.04 LTS tutorials on the Tutorials Hub →
Browse all common problems & solutions on the Tutorials Hub.
References & Further Reading
Ubuntu package dependency and repository management docs.
Need Expert Help?
If you cannot resolve this yourself, our team offers hands-on Server Management, Managed IT Services, and flexible Support Plans. Contact us today — we respond within one business day.