Postmortem: The Git 2.44 and GitHub 3.0 Merge Conflict That Broke Our Production Branch (2026) Executive Summary On January 15, 2026, our team’s production branch (main) became unresponsive after a routine merge of a feature branch, caused by an incompatible interaction between Git 2.44’s new merge strategy logic and GitHub 3.0’s updated branch protection API. The outage lasted 47 minutes, impacting 12% of our API users and delaying 3 scheduled deployments. Timeline of Events 09:12 UTC: Developer opens pull request (PR #8921) merging feature/user-dashboard-v2 into main. 09:14 UTC: GitHub 3.0’s branch protection checks pass; PR is auto-merged per team policy. 09:15 UTC: First alert fires: production health checks fail for main branch deployments. 09:17 UTC: On-call engineer confirms main branch has unresolvable merge conflict markers in 14 core files. 09:22 UTC: Incident declared SEV-1; war room opened.…