Git Common Issues and Fixes Guide

A practical command reference for recovering from common Git mistakes safely.

Goal: help you recover quickly without losing work.

Safety tip: before risky fixes, create a temporary branch: git switch -c rescue/backup-$(date +%Y%m%d-%H%M)

1. "Not a git repository"

# Check current folder
pwd
ls -la

# Enter the correct repository directory
cd /path/to/your/repo

# If needed, initialize a new repo
git init

2. Detached HEAD

# Check status
git status

# Create a branch from current detached commit
git switch -c fix/detached-head-work

# Or return to main branch
git switch main

3. Push Rejected (non-fast-forward)

# Fetch latest remote commits
git fetch origin

# Rebase your branch onto remote
git rebase origin/main

# Resolve conflicts if prompted, then continue
git rebase --continue

# Push after rebase
git push origin main

4. Merge Conflicts

# Start merge/rebase and inspect conflict files
git status

# Edit conflict markers in files, then mark resolved
git add <resolved-file>

# Continue merge/rebase
git merge --continue
# or
git rebase --continue

5. Committed to Wrong Branch

# Example: commit is on main, but should be on feature branch

# 1) Remember latest commit hash
git log --oneline -n 3

# 2) Create target branch from current commit
git switch -c feature/correct-branch

# 3) Return to main and remove wrong commit safely
git switch main
git reset --hard HEAD~1

If the wrong commit was already pushed, use git revert instead of history rewrite on shared branches.

6. Accidentally Lost Commits

# Use reflog to find lost commit refs
git reflog

# Recover by creating a branch at that commit
git switch -c recover/lost-work <commit-hash>

7. Undo Last Commit Safely

# Keep changes staged
git reset --soft HEAD~1

# Keep changes unstaged
git reset --mixed HEAD~1

# Create inverse commit (safe for shared branches)
git revert HEAD

8. Common Error Reference

Error	Likely Cause	Action
`fatal: refusing to merge unrelated histories`	Two repos with unrelated roots	Use `--allow-unrelated-histories` only if intentional
`src refspec ... does not match any`	No commit yet or wrong branch name	Create first commit and verify branch name
`Permission denied (publickey)`	SSH key missing or not registered	Check local SSH key and Git host key registration

9. Quick Health Checks

git status
git branch -vv
git remote -v
git log --oneline --graph --decorate -n 20