Affected versions: CentOS Stream 9

📖 ~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

Installs fail with stream conflict or filtered-candidate errors.

Environment & Reproduction

Appears when a pinned module stream blocks the required runtime.

Root Cause Analysis

A previously enabled module stream persists across upgrades.

Quick Triage

Run `dnf module list –enabled` to identify pinned streams.

Step-by-Step Diagnosis

Use `dnf module info ` to list available streams.

Illustrative mockup for centos-stream-9 — terminal_or_shell
Module stream pin conflict diagnostics in terminal — Illustrative mockup — Progressive Robot

Solution – Primary Fix

Reset the pin: `dnf module reset ` then enable the wanted stream.

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Illustrative mockup for centos-stream-9 — logs_or_journal
journal and log evidence for Module stream pin conflict — Illustrative mockup — Progressive Robot

Solution – Alternative Approaches

Switch streams with `dnf module switch-to :`.

Verification & Acceptance Criteria

Target package installs from the desired stream succeed.

Rollback Plan

Re-enable the prior stream with `dnf module enable` if regressions appear.

Prevention & Hardening

Avoid mixing module streams from third-party repos.

Often paired with AppStream confusion and EPEL conflicts.

Related tutorial: View the step-by-step tutorial for centos-stream-9.

View all centos-stream-9 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Red Hat module documentation and DNF module guide.

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