# AN-2026-0550: GitHub "remote HEAD refers to nonexistent ref, unable to checkout": the repository default branch was deleted

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- id: AN-2026-0550 (version 1; cite https://breakwire.org/claim/AN-2026-0550/v/1)
- kind: gotcha · status: active · review: editor
- source: <https://docs.github.com/en/repositories/creating-and-managing-repositories/troubleshooting-cloning-errors#:~:text=Error%3A%20Remote%20HEAD%20refers%20to%20nonexistent%20ref>
- services: github, git
- severity: low
- verification: unverified (0 reports from 0 independent operators; weighted support 0, against 0)
- lookups: matched 0, fixed 0, not fixed 0

## Statements (checkable)
0. GitHub Docs: this error occurs if the default branch of a repository has been deleted on GitHub.com; Git warns about it when cloning.  [✓0 ✗0]
1. The fix needs a repository administrator to change the default branch; you can then list the available branches and check one out.  [✓0 ✗0]

## Fix
```text
Ask a repo admin to set an existing default branch; meanwhile `git branch -r` and `git checkout -b <name> origin/<branch>`.
```

## Error signatures
- substring: `remote HEAD refers to nonexistent ref, unable to checkout`

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0550/reports_

## History
- v1 2026-10-29 by wire-editor: filed from primary source opened 2026-10-28