Bug Description

The GitHub plugin's release converter crashes with a nil pointer dereference panic when processing certain releases, causing 100% failure rate for all pipelines processing repositories with releases.

Error Details

Error message:

runtime error: invalid memory address or nil pointer dereference
at github.com/apache/incubator-devlake/plugins/github/tasks.ConvertRelease.func1:79

Failure point: Step 30/30 - "Convert Releases" subtask

Root Cause

Commit 794f8ef added a SQL filter to exclude draft releases (published_at IS NOT NULL) but failed to add a defensive nil check before dereferencing the PublishedAt pointer in the converter function at line 79:

PublishedAt:  *githubRelease.PublishedAt,  // Panic if nil!

Impact

• Severity: Critical
• Affected plugin: github_graphql
• Affected operations: All pipelines processing GitHub repositories with releases
• Failure rate: 100% for affected repositories
• Number of observed failures: 10 pipeline tasks (9243, 9259, 9263, 9267, 9271, 9274, 9295, 9310, 9313, 9322)

Environment

• Version: main branch (after commit 794f8ef)
• OS: macOS (Darwin 24.4.0)
• Date observed: October 31, 2025

Reproduction

1. Configure a GitHub connection with repositories that have releases
2. Run a pipeline to collect data from those repositories
3. Observe the pipeline crash at "Convert Releases" step with nil pointer panic

Expected Behavior

The converter should safely handle releases with nil PublishedAt fields, either by:

• Skipping them gracefully (draft releases)
• Logging a warning about data inconsistency

Proposed Solution

Add a nil check before dereferencing the pointer:

if githubRelease.PublishedAt == nil {
    return nil, nil
}

Related

• Related commit: 794f8ef (fix: drafting releases should not be converted to domain layer)
• Pull request with fix: fix: add nil check for PublishedAt in release converter to prevent panic #8628

Additional Context

The SQL filter published_at IS NOT NULL was added to exclude draft releases, but in practice, some releases still have nil PublishedAt fields due to:

• Data inconsistency in the database
• GORM scanning issues
• Invalid timestamps that couldn't be parsed