Git has detected that symbolic references form a loop, where ref A points to ref B, which eventually points back to ref A. This prevents Git from resolving the final target commit.
This error occurs when Git encounters a chain of symbolic references that creates an infinite loop. In Git, a symbolic reference (symref) is a reference that points to another reference rather than directly to a commit hash. For example, HEAD is typically a symref that points to refs/heads/main. Git allows chained symbolic references up to a depth of 5 levels to enable legitimate use cases. However, when these references form a circular chain (A → B → C → A), Git cannot resolve them to an actual commit hash and raises this fatal error. This is a protective mechanism to prevent infinite loops during reference resolution. The error indicates that your repository's reference structure has become corrupted, often due to manual manipulation of refs, file system issues, or interrupted Git operations.
First, examine your repository's symbolic references to identify which refs are involved in the loop:
# Check what HEAD points to
cat .git/HEAD
# List all symbolic refs
find .git/refs -type f -exec sh -c 'echo "=== {} ===" && cat {}' ;
# Check for symref loops
git symbolic-ref HEADIf git symbolic-ref HEAD fails with the circular reference error, HEAD is involved in the loop. Look for refs that start with "ref:" and trace their chain.
Before making any changes, create a backup of your .git directory:
# Create a backup
cp -r .git .git.backup
# Or create a tarball
tar -czf git-backup-$(date +%Y%m%d-%H%M%S).tar.gz .gitThis allows you to restore if something goes wrong during the repair.
Manually fix the circular reference by pointing one of the refs directly to a commit hash:
# If HEAD is involved, point it to your main branch's commit
git log --all --oneline | head -5 # Find a recent commit hash
# Manually set HEAD to point to the main branch
echo "ref: refs/heads/main" > .git/HEAD
# Or point HEAD directly to a commit hash temporarily
echo "commit-hash-here" > .git/HEADIf the circular reference involves branch refs rather than HEAD:
# Delete the problematic ref
rm .git/refs/heads/problematic-branch
# Recreate it pointing to the correct commit
git branch problematic-branch commit-hashAfter breaking the circular reference, verify that your repository is healthy:
# Check repository integrity
git fsck --full
# Verify symbolic references work
git symbolic-ref HEAD
# Test basic operations
git status
git log --oneline -5
# List all branches
git branch -aIf git fsck reports no errors and basic commands work, the circular reference has been resolved.
If you had to point HEAD directly to a commit hash, reattach it to a proper branch:
# Create or checkout the intended branch
git checkout -b main # If branch doesn't exist
# or
git checkout main # If branch exists
# Verify HEAD is now a symbolic ref
cat .git/HEAD
# Should show: ref: refs/heads/mainFor any other affected branches, recreate them using git branch branch-name commit-hash.
### Understanding Git's Symbolic Reference Depth Limit
Git explicitly allows chained symbolic references up to a depth of 5 levels (including HEAD). This means you can have HEAD → branch-alias → actual-branch → commit, with a few levels to spare. The circular reference check protects against infinite loops while allowing legitimate use cases.
### Using Low-Level Plumbing Commands Safely
If you need to manipulate symbolic references programmatically, always use Git's plumbing commands rather than editing files directly:
# Safe: Create/update a symbolic ref
git symbolic-ref refs/heads/alias refs/heads/main
# Safe: Delete a symbolic ref
git symbolic-ref --delete refs/heads/alias
# Unsafe: Direct file manipulation
echo "ref: refs/heads/something" > .git/refs/heads/alias # Risky### Dangling vs Circular References
Don't confuse circular references with dangling symbolic references. A dangling symref points to a branch that doesn't exist yet (common in new repositories where HEAD points to refs/heads/main before the first commit). Dangling refs are harmless; circular refs are fatal errors.
### Prevention in Automation
If you're writing scripts that manipulate Git refs, always validate that you're not creating circular chains:
# Check if a ref is symbolic before modifying
if git symbolic-ref --quiet refs/heads/branch; then
echo "This is a symbolic ref"
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