[BUG] CCR git proxy returns HTTP 503 "Could not verify PR ownership" for all branches — push permanently blocked

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Bug: CCR git proxy returns HTTP 503 for all pushes — permanently blocked

Component: Claude Code / CCR git proxy
Severity: High — blocks all code delivery from Claude Code sessions
Duration: Persisting for several hours; survives proxy restart and incident resolution

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Description

Every git push from a Claude Code session fails with HTTP 503. The proxy's sideband
error is:

ERR Could not verify PR ownership for this branch (GitHub API temporarily unavailable).
Try pushing again.

This affects all branches — claude/* branches, pre-existing branches, and newly
created branches. Retrying does not help.

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Workaround

None available within the Claude Code environment. No gh CLI, no GitHub token,
no MCP GitHub push tools are available to bypass the proxy.

What Should Happen?

'git puth' should succeeed.

Error Messages/Logs

`GIT_TRACE_CURL=1` shows:

- `GET /git/.../info/refs?service=git-receive-pack` → **200 OK** ✅ (discovery works)
- `POST /git/.../git-receive-pack` → sideband returns **ERR**, curl reports **503** ❌

<= Recv data: ERR Could not verify PR ownership for this branch (GitHub AP
<= Recv data: I temporarily unavailable). Try pushing again..
error: RPC failed; HTTP 503 curl 22 The requested URL returned error: 503

Steps to Reproduce

1. Start a Claude Code session on a repository with a CCR remote
2. Make commits on any branch
3. git push origin <branch>

Expected: push succeeds
Actual: HTTP 503, sideband error as above

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Code web Opus 4.6

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

| | |
|---|---|
| GitHub status | All Systems Operational throughout |
| Anthropic status | Incident "Elevated error rates on Opus 4.6" open ~07:00–14:00 UTC 2026-03-27, marked resolved — push failure persists |
| Open PR | Branch claude/add-message-listener-4mpv8 has open PR #6 — ownership check should pass |
| Fetch | Works fine throughout — only push (git-receive-pack) is affected |
| Proxy | Port changed mid-session (36051 → 38283), indicating a restart occurred; failure persisted across restart |
| Repository | liotier/juno106-ouarpeggiator |