How do you troubleshoot Dependabot silently failing to open pull requests?

"Silent" failures — where Dependabot simply never produces an expected PR, with no obvious error visible — usually have a diagnosable root cause once you know where to look, most commonly in the Dependabot logs GitHub provides per configuration.

flowchart TD
    A[Expected PR never appears] --> B[Check Insights - Dependency graph - Dependabot tab logs]
    B --> C{Config parse error?}
    C -->|Yes| D[Fix YAML syntax in dependabot.yml]
    C -->|No| E{Dependency resolution failure?}
    E -->|Yes| F[Conflicting version constraints prevent a valid resolution]
    E -->|No| G{Rate/PR limit already reached?}
    G -->|Yes| H[Merge/close existing PRs to free capacity]

Common root causes include a YAML syntax error in dependabot.yml (which the logs will flag explicitly), an unresolvable dependency conflict where no valid combination of versions satisfies every constraint simultaneously, or simply having already hit the configured open-pull-requests-limit — the Dependabot-specific logs (distinct from a repository's regular Actions logs) are the essential first stop for this kind of investigation.