Git Troubleshooting Advance Guides – aiuniverse

Here’s a guide to addressing several advanced Git issues, complete with solutions:

1. Resolving Merge Conflicts

Problem: Merge conflicts occur when Git is unable to automatically resolve differences in code between two commits.
Solution:

• Use git status to identify the conflicted files.
• Open the conflicted files and make the necessary changes.
• After resolving conflicts, use git add <file> to mark them as resolved.
• Commit the resolved files with git commit.

2. Recovering Lost Commits

Problem: Sometimes commits can be lost during rebasing or other Git operations.
Solution:

• Use git reflog to find the lost commits. This command shows a log of where your HEAD and branch references have been.
• Once you identify the lost commit, check it out using git checkout <commit-hash> or cherry-pick it to your current branch with git cherry-pick <commit-hash>.

3. Reverting a Pushed Merge

Problem: If a merge has been pushed to a shared repository but needs to be undone, a simple git revert won’t suffice as it will leave the history of both branches.
Solution:

• To revert the merge and maintain the history, use git revert -m 1 <merge-commit-hash>. The -m 1 specifies which parent branch of the merge you want to keep.

4. Cleaning Up Excessive Branches

Problem: Over time, a repository can accumulate many outdated or merged branches.
Solution:

• To delete branches that have been merged into master, use git branch --merged master | grep -v "master" | xargs git branch -d.
• For remote branches, first fetch the latest state with git fetch -p, then delete outdated branches with git remote prune origin or individually by git push origin --delete <branch-name>.

5. Handling Large Files or Repositories

Problem: Large files can slow down Git operations and cause storage issues.
Solution:

• Implement Git Large File Storage (LFS) for handling large files.
• To convert existing files to LFS, use git lfs track "*.filetype" and then git add . && git commit -m "Track large files with LFS".

6. Fixing Broken References or Corruption

Problem: Corruption in the .git directory can lead to broken references.
Solution:

• Run git fsck --full to check the integrity of your Git database.
• If corruption is detected, you may need to clone the repository again or restore lost objects from backups.

7. Undoing a Git Rebase

Problem: A rebase can sometimes go wrong, leaving the project in an undesired state.
Solution:

• Use git reflog to find the commit hash before the rebase started.
• Reset the branch to that commit using git reset --hard <commit-hash>.

8. Advanced Searching in Repository History

Problem: Finding specific changes or related commits in large repositories.
Solution:

• Use git log -S<string> to search for commits that added or removed a specific string.
• git bisect helps you to manually identify the commit that introduced a bug by binary search.

These solutions are typically sufficient for solving most advanced issues you’ll encounter with Git. For complex problems that involve repository history and data integrity, it’s often wise to back up your data before performing operations that rewrite history (like rebase or reset).