[Bug]: Server-Side 500 Internal Server Error on Git Reference Updates (commit_refs) for repository 1440183363

[sethusrinivasan]

GitHub Service Incident Report: Server-Side 500 Internal Server Error on Git Reference Updates (commit_refs)

Ticket Category: Git Infrastructure / Core Services / Reference Transaction Engine
Severity: High (Blocking all code pushes & branch ref updates to repository)
Date & Time: 2026-11-05 00:25:32 UTC (Local: 2026-11-04 16:25:32 PDT)
Repository: sethusrinivasan/dhayam
Repository ID: 1440183363 (node_id: R_kgDOVdd0Qw)
Account / Owner: sethusrinivasan (id: 3907049)
Impacted Branch / Ref: refs/heads/main (and all attempts to create new branch refs)

---

1. Executive Summary

Attempts to update refs/heads/main or create any new branch references in sethusrinivasan/dhayam fail consistently with a server-side error:

• Git Smart HTTP Protocol: remote: fatal error in commit_refs → ! [remote rejected] main -> main (failure)
• GitHub REST API (PATCH /repos/sethusrinivasan/dhayam/git/refs/heads/main): HTTP/2 500 Internal Server Error with empty response body (Content-Length: 0).
• GitHub REST API (POST /repos/sethusrinivasan/dhayam/git/refs): HTTP/2 422 Unprocessable Entity ("Reference update failed").

Crucially, Git object transfer succeeds: commit object d9bfaed855325d26dc820459b6d3132f661c7eb1 (along with all tree and blob dependencies) was unpacked and persisted in GitHub's object store. The failure is strictly isolated to GitHub's internal reference transaction backend (commit_refs / ref database locking).

---

2. GitHub Traceability & Request IDs

The issue reproduces across multiple GitHub edge regions. Here are exact trace headers from live occurrences:

Timestamp (UTC)	GitHub Edge Region	HTTP Status	GitHub Request ID (X-GitHub-Request-Id)	Operation
2026-11-05 00:25:32 GMT	westus2	500 Internal Server Error	D05E:DE9E7:1A8C37:2D3D4E:6AEBCCFA	PATCH /git/refs/heads/main
2026-11-05 00:23:42 GMT	sea	500 Internal Server Error	C5C0:1640:16030E0:1F5A403:6AEBCC8C	PATCH /git/refs/heads/main
2026-11-05 00:17:08 GMT	westus2	500 Internal Server Error	E626:FCAD6:1A29F0:2C8448:6AEBCB02	PATCH /git/refs/heads/main
2026-11-05 00:23:29 GMT	sea	422 Unprocessable Entity	A488:316A9F:1C04364:27B82FF:6AEBCC7F	POST /git/refs
2026-11-05 00:17:15 GMT	westus2	422 Unprocessable Entity	CF3E:2FB765:1A5F4F:2CACA7:6AEBCB08	POST /git/refs

---

3. Evidence of Successful Object Ingestion

To confirm this is not a packfile corruption, transmission drop, or malformed Git object:
A GET request to GitHub's commit object endpoint for the target commit SHA returns 200 OK with the full commit payload:

GET https://api.github.com/repos/sethusrinivasan/dhayam/git/commits/d9bfaed855325d26dc820459b6d3132f661c7eb1

Response:

{
  "sha": "d9bfaed855325d26dc820459b6d3132f661c7eb1",
  "node_id": "C_kwDOVdd0Q9oAKGQ5YmZhZWQ4NTUzMjVkMjZkYzgyMDQ1OWI2ZDMxMzJmNjYxYzdlYjE",
  "author": {
    "name": "Sethu Srinivasan",
    "email": "sethusrinivasan@gmail.com",
    "date": "2026-11-05T00:15:42Z"
  },
  "committer": {
    "name": "Sethu Srinivasan",
    "email": "sethusrinivasan@gmail.com",
    "date": "2026-11-05T00:15:42Z"
  },
  "tree": {
    "sha": "e8924573969dbc8dad5ca899869258b9bd940cd7"
  },
  "message": "feat: expand festive themes, add roll secret entropy, and stabilize CI test suites",
  "parents": [
    {
      "sha": "1d78fb6598e78ad8fd999125dc4f9e6d692bf25b"
    }
  ]
}

This establishes that GitHub has already validated the parent graph, tree objects, and commit tree-ish. Only the final ref pointing step (refs/heads/main -> d9bfaed...) crashes.

---

4. Policy, Permission & Configuration Audit

We verified all permission boundaries to eliminate client-side configuration causes:

1. Repository Access Level:
   • permissions: { "admin": true, "maintain": true, "push": true }
   • role_name: "admin"
2. Branch Protection:
   • GET /repos/sethusrinivasan/dhayam/branches/main/protection → HTTP 404 (Branch not protected)
3. Repository Rulesets:
   • GET /repos/sethusrinivasan/dhayam/rulesets → [] (no rulesets active)
4. Secret Scanning Push Protection:
   • security_and_analysis.secret_scanning_push_protection.status: "disabled"
5. OAuth Token Scopes:
   • X-OAuth-Scopes: gist, read:org, repo, workflow

---

5. Step-by-Step Reproduction Commands

Method A: Git Smart HTTP (git-receive-pack)

git push origin main

Terminal Output:

Writing objects: 100% (30/30), 9.09 KiB | 9.09 MiB/s, done.
Total 30 (delta 26), reused 0 (delta 0), pack-reused 0 (from 0)
remote: Resolving deltas: 100% (26/26), completed with 26 local objects.
remote: fatal error in commit_refs
To https://github.com/sethusrinivasan/dhayam.git
 ! [remote rejected] main -> main (failure)
error: failed to push some refs to 'https://github.com/sethusrinivasan/dhayam.git'

Method B: REST API Reference Update

curl -i -X PATCH https://api.github.com/repos/sethusrinivasan/dhayam/git/refs/heads/main \
  -H "Authorization: Bearer <TOKEN>" \
  -H "Accept: application/vnd.github+json" \
  -H "Content-Type: application/json" \
  -H "X-GitHub-Api-Version: 2022-11-28" \
  -d '{"sha":"d9bfaed855325d26dc820459b6d3132f661c7eb1","force":false}'

HTTP Response:

HTTP/2 500 
date: Thu, 05 Nov 2026 00:25:32 GMT
content-type: application/json; charset=utf-8
content-length: 0
server: github.com
x-github-request-id: D05E:DE9E7:1A8C37:2D3D4E:6AEBCCFA
x-github-edge-region: westus2

---

6. Suspected Engineering Causes

Based on GitHub's Git architecture (DGit/Spokes and reference transaction managers):

1. Stale Lockfile / Ref Lock: A previous push event (e.g. at 2026-11-03T22:59:39Z) or background CI dispatch may have left an unreleased lockfile on the remote storage node (e.g., refs/heads/main.lock or a locked packed-refs transaction).
2. DGit / Spokes Replica Quorum Conflict: Out-of-sync or unresponsive storage server replicas in cluster westus2/sea preventing the reference update transaction from committing across the quorum.
3. Reference Storage DB Corruption: An internal inconsistency in the repository's reference database preventing writes to any refs/heads/* ref namespace.

---

7. Requested Action from GitHub Support / Engineering

1. Inspect internal application logs for X-GitHub-Request-Id: D05E:DE9E7:1A8C37:2D3D4E:6AEBCCFA and C5C0:1640:16030E0:1F5A403:6AEBCC8C.
2. Clear any lingering stale ref locks (*.lock) or stalled transactions on the storage nodes hosting repository 1440183363.
3. Run a git fsck and reference consistency verification across all active DGit replicas for sethusrinivasan/dhayam.
4. Point refs/heads/main to already-ingested commit d9bfaed855325d26dc820459b6d3132f661c7eb1.

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[sethusrinivasan]

Google Gemini helped submit this report. Where else should this service issue be reported to?