Fix 'The branch is not fully merged' when deleting in Git

Overview

Git blocks git branch -d <name> if the branch’s commits are not reachable from your current branch (often main or develop). This protects unmerged work from accidental loss. You can:

• Integrate the work (merge, rebase, or cherry-pick), then delete.
• Decide to discard it and force-delete (-D) after a quick safety check.

This guide shows practical, DevOps-friendly steps to resolve the message safely.

Quickstart (most common fixes)

• See what’s unmerged:
  • git branch --no-merged
  • git log --oneline --left-right --cherry-pick --graph main...feature
• Merge the branch into your target:
  • git checkout main && git merge --no-ff feature
• Or pick specific commits:
  • git checkout main && git cherry-pick <commit1> <commit2>
• If discarding on purpose, make a backup tag and force-delete:
  • git tag backup/feature feature && git branch -D feature
• Delete remote branch (if needed):
  • git push origin --delete feature && git fetch -p

Minimal working example

This demonstrates the error and three ways to fix it.

# 1) Setup demo repo
mkdir demo && cd demo
git init -b main
printf "one\n" > file.txt
git add file.txt && git commit -m "init"

# 2) Create a feature branch with unique commits
git checkout -b feature
echo "feature A" >> file.txt
git commit -am "feat: add A"
echo "feature B" >> file.txt
git commit -am "feat: add B"

# 3) Switch back and try to delete (will fail)
git checkout main
git branch -d feature
# -> The branch 'feature' is not fully merged ...

# Fix Option A: Merge the work
git merge --no-ff feature
git branch -d feature  # now succeeds

# Reset to before merge to try other options (demo only)
git reset --hard HEAD~1

# Fix Option B: Cherry-pick specific commit(s)
git log --oneline main..feature   # list unique commits
git cherry-pick <hash-of-desired-commit>
git branch -d feature

# Fix Option C: Force-delete after making a backup tag
git tag backup/feature feature
git branch -D feature

Step-by-step resolution

1. Confirm target branch

• Ensure you’re on the branch that should contain the work (e.g., main).
• git rev-parse --abbrev-ref HEAD

1. Identify unmerged work

• List branches not fully merged into your current branch:
  • git branch --no-merged
• Compare differences (symmetric diff):
  • git log --oneline --left-right --cherry-pick --graph main...feature
• Show commits unique to feature:
  • git log --oneline main..feature
• Diff actual changes:
  • git diff main...feature

1. Decide how to handle the changes

• Merge (keeps history): git checkout main && git merge --no-ff feature
• Squash merge (single commit): git checkout main && git merge --squash feature && git commit
• Rebase feature onto main, then fast-forward merge:
  • git checkout feature && git rebase main && git checkout main && git merge feature
• Cherry-pick selected commits onto main:
  • git checkout main && git cherry-pick <commit1> [<commit2> ...]

1. Delete the local branch

• Safe delete (only if fully merged): git branch -d feature
• Force delete (discarding remaining work):
  • Optional backup: git tag backup/feature feature
  • Force delete: git branch -D feature

1. Delete the remote branch (if applicable)

• git push origin --delete feature
• Clean up local stale tracking refs: git fetch -p

1. Verify cleanup

• git branch --all --list '*feature*'

When to use each option

• Merge or squash merge: You want to keep the branch’s work and history (or a condensed form) in the target branch.
• Cherry-pick: Only some commits are desired.
• Force delete: You intentionally discard remaining work (back it up first with a tag or note the commit hashes).

Common pitfalls

• Deleting the checked-out branch: Switch away first (git checkout main).
• Confusing local vs remote: git branch -d affects local branches only. Remote deletion uses git push origin --delete <name>.
• Protected branches: Remotes (GitHub/GitLab) may block deletion; adjust protections or use an admin workflow.
• Orphaned work after force-delete: Without a tag or note of commit IDs, finding the commits later is harder.
• Assuming PR merge equals Git merge: Squash/rebase merges may create new commit IDs; confirm the target branch truly contains the changes: git log --cherry-pick --oneline main...feature.

Recovery tips (if you deleted too soon)

• Find the last commit of the deleted branch in the reflog:
  • git reflog | grep feature (or inspect recent entries)
• Recreate the branch from the commit:
  • git branch feature <commit>
• If remote was deleted but others still have it, fetch from a peer or the remote’s refs if available.

DevOps considerations

• CI/CD pipelines: Delete branches after merging to reduce clutter, but only after green pipelines and artifact publication.
• Branch protection policies: Require reviews/status checks and allow branch deletion only after merge.
• Automation: In cleanup scripts, check merged status first:

#!/usr/bin/env bash
set -euo pipefail
base=${1:-main}
for b in $(git for-each-ref --format='%(refname:short)' refs/heads/); do
  [[ "$b" == "$base" ]] && continue
  if git merge-base --is-ancestor "$b" "$base"; then
    git branch -d "$b"
  fi
done

Performance notes

• Large repos: Prefer commit-range operations over full diffs when deciding merge status:
  • git merge-base --is-ancestor feature main is fast and reliable.
• Fetch pruning: git fetch -p keeps refs lean and speeds up branch listings.
• Commit-graph: Enable for faster history queries:
  • git config --global core.commitGraph true && git commit-graph write --reachable

FAQ

• What does “not fully merged” mean?
  • The target branch (usually your current branch) doesn’t contain all commits from the branch you’re deleting.
• Is -D safe?
  • It force-deletes even if unmerged. Use only after verifying diffs or tagging a backup.
• Do I need to merge before deleting a remote branch?
  • No. Remotes typically allow deletion regardless of merge state, unless protections apply.
• How do I check if a branch is merged into a specific target?
  • git merge-base --is-ancestor feature main (exit code 0 means merged).