Git Troubleshooting Cheat Sheet

Common Git errors and fixes — detached HEAD, merge conflicts, push rejected, divergent branches, authentication issues, and recovery techniques.

Last Updated: May 1, 2025

Detached HEAD

git status

Reports 'HEAD detached at commit' — you're not on a branch

git switch -c new-branch

Create a new branch at current commit (safest)

git checkout -b new-branch

Alternative: create branch at detached HEAD

git switch main

Abandon detached HEAD (commits may be lost!)

git branch temp HEAD

Save detached HEAD commits to a named branch

git reflog

Find lost detached HEAD commits by their reflog entries

Merge Conflicts

git status

Shows 'both modified' — files with conflicts

git diff --name-only --diff-filter=U

List only conflicted files

git checkout --ours file

Accept OUR version of a conflicted file

git checkout --theirs file

Accept THEIR version of a conflicted file

git mergetool

Launch visual merge tool (vscode, kdiff3, etc.)

git merge --abort

Cancel the entire merge and return to pre-merge state

git add file && git merge --continue

After resolving, stage and continue

git config --global merge.conflictstyle diff3

Show base version in conflict markers

Push Rejected

git pull --rebase origin main

Your local is behind — fetch, rebase, then push

git push --force-with-lease

Force push safely (respects others' changes)

git push -f

DANGEROUS: force push (overwrites remote completely)

git fetch origin && git diff main origin/main

See what's different on remote

git fetch origin && git rebase origin/main

Sync your branch with remote before pushing

git push -u origin branch

Set upstream: 'no upstream branch' error

Common Error Quick Fixes

Error	Cause	Fix
fatal: not a git repository	Not in a repo directory	cd to repo or git init
fatal: refusing to merge unrelated histories	Two repos with no common ancestor	git merge --allow-unrelated-histories
fatal: unable to access... SSL certificate problem	SSL cert issue	git config --global http.sslVerify false (temporary)
error: Your local changes... would be overwritten	Uncommitted changes conflict with checkout	git stash then checkout
warning: LF will be replaced by CRLF	Line ending mismatch	git config --global core.autocrlf input
You have divergent branches	Local and remote diverged	git pull --rebase or git reset --hard origin/main
remote: Permission denied	SSH key or access issue	Check ssh -T [email protected]
error: failed to push some refs	Remote has newer commits	Pull first: git pull --rebase

Pro Tip: Stay calm — Git rarely loses data permanently. The reflog, fsck, and detached HEAD recovery can get you out of almost any mess.