Hi, My configuration: OS Kubuntu 24.04 Git version: 2.54.0 from ppa:git-core/ppa

.gitconfig
[merge]
     guitool = meld
     tool = meld
[core]
     editor = code -w
     autocrlf = input
     quotePath = false
     eol = lf

[global]
[diff]
     tool = meld
[gui]
     editor = code
[fetch]
     prune = true
[mergetool]
     keepBackup = false

How to reproduce:
1) Made repo
# Init repo with README.md
git init
echo -e '# Git rebase bug\n\n```\ngit rebase master\ngit mergetool\ngit 
rebase --continue\ngit rev-parse REBASE_HEAD\n```' > README.md
git add README.md
git commit -m "docs: add README.md"

# Add feature branch git branch feature_branch

# Add files in separate commits echo -e "Text 1 line\nText 2 line\nText 3 line\nText 4 line\nText 5 line" > Text1.txt git add Text1.txt git commit -m "feat: add Text1.txt"

echo -e "Text 1 line\nText 2 line\nText 3 line\nText 4 line\nText 5 line" > Text2.txt git add Text2.txt git commit -m "feat: add Text2.txt"

echo -e "Text 1 line\nText 2 line\nText 3 line\nText 4 line\nText 5 line" > Text3.txt git add Text3.txt git commit -m "feat: add Text3.txt"

# Do the same in feature branch and one more in one commit git checkout feature_branch echo -e "Texts 1 line\nTexts 2 line\nTexts 3 line\nText 4 line\nTexts 5 line" > Text1.txt git add Text1.txt

echo -e "Text 1 line\nText 2 line\nText 3 line\nText 4 line\nText 5 line" > Text2.txt git add Text2.txt

echo -e "Texts 1 line\nTexts 2 line\nTexts 3 line\nText 4 line\nTexts 5 line" > Text3.txt git add Text3.txt

echo -e "Texts 1 line\nTexts 2 line\nText 3 line\nTexts 4 line\nText 5 
line" > Text4.txt
git add Text4.txt
git commit -m "feat: add all files"
2) Call — git rebase master
3) Call — git mergetool
4) Call — git rebase --continue
5) Call — git rev-parse REBASE_HEAD
Last command return value and .git/REBASE_HEAD exists.
In other words REBASE_HEAD exists if ogirinal commit in new branch 
modified and need call git push --force to send it to server. Please fix 
it, thanks!

-- Long76

On Tue Jul 28, 2026 at 4:26 AM EDT, Long 76 wrote:

I ran into this not that long ago too, while working on a script. It looked like this behavior depended on how the _last_ item in the rebase todo list was handled. I found if the last action was a squash or edit (I don't think reword did this), then REBASE_HEAD was left behind.

Also, if rebase stops on a break command, then REBASE_HEAD will be missing, even though a rebase is still in-progress.

I made a very short-lived effort to look into why this "bug" was happening. I say "bug" in quotes, because I'm not even sure if it is even problematic behavior.

I solved my need at the time (detecting a rebase in progress) by checking for the existence of either of the 'rebase-merge' or 'rebase-apply' directories in $GIT_DIR.

On 28/07/2026 10:39, Matt Hunter wrote:

The need for "--force" when pushing is due to you having rebased the branch, it is unrelated to the existence of REBASE_HEAD (other than the fact that it exists indicates you have rebased). Rebasing rewrites the history which means that the remote cannot fast-forward when you push. Rather than using "--force" I'd recommend "--force-with-lease --force-if-includes" instead (see the "git push" man page for more details).

I think leaving REBASE_HEAD behind after a rebase is a bug, albeit not a very serious one. Looking at the code we delete it before processing each command, but do not clean it up after the last command.

That's the best way to detect if a rebase is in progress - REBASE_HEAD only exists when there are conflicts, or the editor is opened for the user to reword a commit. It does not exist when the user is editing the todo list at the start of a rebase; when stopping for conflicts after a "merge parent" command without "-C"; when stopping for a break or failed exec command.

Thanks

Phillip

I know it, commit don't the same that was before rebase - because of the conflict, it had to be changed.

I think this is a bug because git create similar HEADs if you made merge or cherry-pick. I don't have problems with them.

Plus by git rebase docs on official site flag '--show-current-patch': --- Show the current patch in an interactive rebase or when rebase is stopped because of conflicts. This is the equivalent of git show REBASE_HEAD. --- For me it means that return patch only if rebase in progress - not aborted/not complete/have conflicts

Thanks for advice! I don't knew it.

+ phillip.wood@dunelm.org.uk

28.07.2026 18:27, Long 76 пишет: