Git “failed to push some refs” / Non-Fast-Forward: Fix It Safely Without Losing Work

When you run `git push origin main`, Git rejects the operation with: ```bash To github.com:user/repo.git ! [rejected] main -> main (non-fast-forward) error: failed to push some refs to 'github.com:user/repo.git' hint: Updates were rejected because the tip of your current branch is behind hint: its remote counterpart. Integrate the remote changes... ``` This occurs because someone else (or you, via the GitHub web editor or README initialization) added commits to the remote branch that your local machine does not have yet. Git refuses to overwrite those remote commits.

Never run `git push --force` on shared code. Follow these three commands: ### Step 1: Pull and Rebase Remote Changes ```bash git pull --rebase origin main ``` This temporarily sets your local commits aside, applies the new commits from GitHub, and then replays your local commits on top of the latest version. ### Step 2: Resolve Any Conflicts (If Prompted) If you edited the same lines as remote commits, Git will pause and flag conflicts. Open the conflicting file, choose the correct code, and run: ```bash git add . git rebase --continue ``` ### Step 3: Push Successfully Once the rebase completes: ```bash git push origin main ``` Your commits are pushed cleanly with a linear commit history.