From: Alejandro Colomar <alx@kernel.org>
To: phillip.wood@dunelm.org.uk
Cc: Patrick Steinhardt <ps@pks.im>,
git@vger.kernel.org, Nico Williams <nico@cryptonector.com>
Subject: Re: git-rebase-walk
Date: Mon, 5 Oct 2026 15:28:21 +0200 [thread overview]
Message-ID: <asOaLyiJUmINFFFH@debian> (raw)
In-Reply-To: <95796d0d-5928-4108-bc27-b7ace4459d2a@gmail.com>
[-- Attachment #1: Type: text/plain, Size: 18337 bytes --]
Hi Phillip,
> Date: 2026-10-04 11:03:39+0100
> From: Phillip Wood <phillip.wood123@gmail.com>
>
> On 02/10/2026 07:46, Patrick Steinhardt wrote:
> > On Thu, Oct 01, 2026 at 05:51:58PM +0200, Alejandro Colomar wrote:
> > >
> > > My script I use it in shadow-utils and in the Linux man-pages project,
> > > and is in use today. I was wondering if there was interest in
> > > integrating it to git(1).
> >
> > I guess the answer is "maybe". The fact that multiple folks have solved
> > similar issues over the course of many years is an indicator that the
> > funcitonality may be more generally useful. But it probably shouldn't be
> > a separate script, so if we wanted to integrate it I'd think the best
> > way forward would be to integrate it into git-rebase(1) directly.
>
> I agree that would be the best way forward. Adding an "--incremental", or
> "--progressive" option to rebase would be useful I think. For ease of use, I
> have a strong preference for an implementation where "rebase --continue"
> handles rebasing onto progressively more recent bases, rather than the multi
> shot approach where the user has to run "git rebase --incremental" multiple
> times. Having a multi-shot approach makes it much less clear when we've
> successfully rebased onto the desired base.
For rebasing a single branch, having --continue do what you suggest
wouldn't be too problematic.
However, for when rebasing a tree of branches, I really need a
multi-shot operation, since I want to advance branches in a very
specific order.
Below is a shell session performing such a rebase, which hopefully shows
why I need this to be multi-shot.
On the simpler case of a single branch, I'd still prefer a multi-shot
approach where --continue only advances one rebase operation, because at
the end of it I want to stop, and check git-range-diff(1) to make sure
it all makes sense.
I've indented the output of commands, so that they are easier to
distinguish.
alx@debian:~/tmp/brebase$ git log --all --graph --oneline
* G ada8aff4f08a (r/B, B) foo j
* G d6163efdc2db bar i
| * G 450f3a7f4f25 (r/HEAD, r/C, C) bar l
| * G f7309b21ebfa bar k
|/
* G e949e24ba457 (HEAD -> A, r/A) bar h
* G 607b450498be bar g
|\
| * G b787bcd373d9 bar e
* | G c496b325576f baz f
|/
| * G dfd9156d099a (r/main, main) foo d
| * G 4940c7d739be bar c
| * G cebc8fde25bb foo b
|/
* G 1dcb901ebf60 foo a
alx@debian:~/tmp/brebase$ git brebase --rebase-merges main
Rebase: conflict
Bisecting: 0 revisions left to test after this (roughly 1 step)
[4940c7d739be44c0ca32c1d610b85fd5650e1528] bar c
running '.git/bisect-rebase/git-bisect-run-callback'
Rebase: conflict
Bisecting: 0 revisions left to test after this (roughly 0 steps)
[cebc8fde25bbe16c0f5f48e39642b3551f4f56e6] foo b
running '.git/bisect-rebase/git-bisect-run-callback'
Rebase: success
4940c7d739be44c0ca32c1d610b85fd5650e1528 is the first 'bad' commit
commit 4940c7d739be44c0ca32c1d610b85fd5650e1528
Author: Alejandro Colomar <alx@kernel.org>
Date: 2026-10-05 14:42:32 +0200
bar c
bar | 1 +
1 file changed, 1 insertion(+)
create mode 100644 bar
bisect found first 'bad' commit
Auto-merging bar
CONFLICT (add/add): Merge conflict in bar
error: could not apply 899eeb5c4e32... bar e
hint: Resolve all conflicts manually, mark them as resolved with
hint: "git add/rm <conflicted_files>", then run "git rebase --continue".
hint: You can instead skip this commit: run "git rebase --skip".
hint: To abort and get back to the state before "git rebase", run "git rebase --abort".
hint: Disable this message with "git config set advice.mergeConflict false"
Could not apply 899eeb5c4e32... # bar e
alx@debian:~/tmp/brebase$ git rebase --abort
alx@debian:~/tmp/brebase$ git log --all --graph --oneline
* 655c38e3cee8 (HEAD -> A) bar h
* 1ababced193d bar g
|\
| * 899eeb5c4e32 bar e
* | 761c9dbcfa5b baz f
|/
| * ada8aff4f08a (r/B, B) foo j
| * d6163efdc2db bar i
| | * 450f3a7f4f25 (r/HEAD, r/C, C) bar l
| | * f7309b21ebfa bar k
| |/
| * e949e24ba457 (r/A) bar h
| * 607b450498be bar g
| |\
| | * b787bcd373d9 bar e
| * | c496b325576f baz f
| |/
| | * dfd9156d099a (r/main, main) foo d
| | * 4940c7d739be bar c
| |/
|/|
* | cebc8fde25bb foo b
|/
* 1dcb901ebf60 foo a
alx@debian:~/tmp/brebase$ git switch B
Switched to branch 'B'
Your branch is up to date with 'r/B'.
alx@debian:~/tmp/brebase$ git brebase A
Rebase: conflict
Bisecting: 2 revisions left to test after this (roughly 1 step)
[899eeb5c4e32397f0fe138c5b9f486d4682939cb] bar e
running '.git/bisect-rebase/git-bisect-run-callback'
Rebase: conflict
Bisecting: 0 revisions left to test after this (roughly 0 steps)
[cebc8fde25bbe16c0f5f48e39642b3551f4f56e6] foo b
running '.git/bisect-rebase/git-bisect-run-callback'
Rebase: conflict
cebc8fde25bbe16c0f5f48e39642b3551f4f56e6 is the first 'bad' commit
commit cebc8fde25bbe16c0f5f48e39642b3551f4f56e6
Author: Alejandro Colomar <alx@kernel.org>
Date: 2026-10-05 14:42:04 +0200
foo b
foo | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
bisect found first 'bad' commit
Auto-merging foo
CONFLICT (content): Merge conflict in foo
error: could not apply ada8aff4f08a... foo j
hint: Resolve all conflicts manually, mark them as resolved with
hint: "git add/rm <conflicted_files>", then run "git rebase --continue".
hint: You can instead skip this commit: run "git rebase --skip".
hint: To abort and get back to the state before "git rebase", run "git rebase --abort".
hint: Disable this message with "git config set advice.mergeConflict false"
Could not apply ada8aff4f08a... # foo j
alx@debian:~/tmp/brebase$ echo j >foo
alx@debian:~/tmp/brebase$ git add foo
alx@debian:~/tmp/brebase$ git rebase --continue
[detached HEAD 2e0b72e7440a] foo j
1 file changed, 1 insertion(+), 1 deletion(-)
Successfully rebased and updated refs/heads/B.
alx@debian:~/tmp/brebase$ git log --all --graph --oneline
* 2e0b72e7440a (HEAD -> B) foo j
* a1c6c1fb7ca2 bar i
* d8fa6c4da463 bar h
* bef9f1c4da4d bar e
* 0bac26895b94 baz f
| * 655c38e3cee8 (A) bar h
| * 1ababced193d bar g
| |\
| | * 899eeb5c4e32 bar e
| |/
|/|
| * 761c9dbcfa5b baz f
|/
| * ada8aff4f08a (r/B) foo j
| * d6163efdc2db bar i
| | * 450f3a7f4f25 (r/HEAD, r/C, C) bar l
| | * f7309b21ebfa bar k
| |/
| * e949e24ba457 (r/A) bar h
| * 607b450498be bar g
| |\
| | * b787bcd373d9 bar e
| * | c496b325576f baz f
| |/
| | * dfd9156d099a (r/main, main) foo d
| | * 4940c7d739be bar c
| |/
|/|
* | cebc8fde25bb foo b
|/
* 1dcb901ebf60 foo a
alx@debian:~/tmp/brebase$ git brebase A
Rebase: success
alx@debian:~/tmp/brebase$ git log --all --graph --oneline
* 5ff93a00f9f2 (HEAD -> B) foo j
* 01522206a7bc bar i
* 655c38e3cee8 (A) bar h
* 1ababced193d bar g
|\
| * 899eeb5c4e32 bar e
* | 761c9dbcfa5b baz f
|/
| * ada8aff4f08a (r/B) foo j
| * d6163efdc2db bar i
| | * 450f3a7f4f25 (r/HEAD, r/C, C) bar l
| | * f7309b21ebfa bar k
| |/
| * e949e24ba457 (r/A) bar h
| * 607b450498be bar g
| |\
| | * b787bcd373d9 bar e
| * | c496b325576f baz f
| |/
| | * dfd9156d099a (r/main, main) foo d
| | * 4940c7d739be bar c
| |/
|/|
* | cebc8fde25bb foo b
|/
* 1dcb901ebf60 foo a
alx@debian:~/tmp/brebase$ git switch C
Switched to branch 'C'
alx@debian:~/tmp/brebase$ git brebase A
Rebase: success
alx@debian:~/tmp/brebase$ git log --all --graph --oneline
* 06d462903420 (HEAD -> C) bar l
* 20f0a887b83b bar k
| * 5ff93a00f9f2 (B) foo j
| * 01522206a7bc bar i
|/
* 655c38e3cee8 (A) bar h
* 1ababced193d bar g
|\
| * 899eeb5c4e32 bar e
* | 761c9dbcfa5b baz f
|/
| * ada8aff4f08a (r/B) foo j
| * d6163efdc2db bar i
| | * 450f3a7f4f25 (r/HEAD, r/C) bar l
| | * f7309b21ebfa bar k
| |/
| * e949e24ba457 (r/A) bar h
| * 607b450498be bar g
| |\
| | * b787bcd373d9 bar e
| * | c496b325576f baz f
| |/
| | * dfd9156d099a (r/main, main) foo d
| | * 4940c7d739be bar c
| |/
|/|
* | cebc8fde25bb foo b
|/
* 1dcb901ebf60 foo a
alx@debian:~/tmp/brebase$ git switch A
Switched to branch 'A'
alx@debian:~/tmp/brebase$ git brebase --rebase-merges main
Rebase: conflict
Bisecting: 0 revisions left to test after this (roughly 0 steps)
[4940c7d739be44c0ca32c1d610b85fd5650e1528] bar c
running '.git/bisect-rebase/git-bisect-run-callback'
Rebase: conflict
4940c7d739be44c0ca32c1d610b85fd5650e1528 is the first 'bad' commit
commit 4940c7d739be44c0ca32c1d610b85fd5650e1528
Author: Alejandro Colomar <alx@kernel.org>
Date: 2026-10-05 14:42:32 +0200
bar c
bar | 1 +
1 file changed, 1 insertion(+)
create mode 100644 bar
bisect found first 'bad' commit
Auto-merging bar
CONFLICT (add/add): Merge conflict in bar
error: could not apply 899eeb5c4e32... bar e
hint: Resolve all conflicts manually, mark them as resolved with
hint: "git add/rm <conflicted_files>", then run "git rebase --continue".
hint: You can instead skip this commit: run "git rebase --skip".
hint: To abort and get back to the state before "git rebase", run "git rebase --abort".
hint: Disable this message with "git config set advice.mergeConflict false"
Could not apply 899eeb5c4e32... # bar e
alx@debian:~/tmp/brebase$ echo e >bar
alx@debian:~/tmp/brebase$ git add bar
alx@debian:~/tmp/brebase$ git rebase --continue
[detached HEAD 2a4fa7fe2f44] bar e
1 file changed, 1 insertion(+), 1 deletion(-)
Successfully rebased and updated refs/heads/A.
alx@debian:~/tmp/brebase$ git log --all --graph --oneline
* 0954f3d9b9e1 (HEAD -> A) bar h
* 4f09c21bf2ca bar g
|\
| * 2a4fa7fe2f44 bar e
* | e42246e75159 baz f
|/
| * 06d462903420 (C) bar l
| * 20f0a887b83b bar k
| | * 5ff93a00f9f2 (B) foo j
| | * 01522206a7bc bar i
| |/
| * 655c38e3cee8 bar h
| * 1ababced193d bar g
| |\
| | * 899eeb5c4e32 bar e
| * | 761c9dbcfa5b baz f
| |/
| | * ada8aff4f08a (r/B) foo j
| | * d6163efdc2db bar i
| | | * 450f3a7f4f25 (r/HEAD, r/C) bar l
| | | * f7309b21ebfa bar k
| | |/
| | * e949e24ba457 (r/A) bar h
| | * 607b450498be bar g
| | |\
| | | * b787bcd373d9 bar e
| | * | c496b325576f baz f
| | |/
| | | * dfd9156d099a (r/main, main) foo d
| |_|/
|/| |
* | | 4940c7d739be bar c
|/ /
* / cebc8fde25bb foo b
|/
* 1dcb901ebf60 foo a
alx@debian:~/tmp/brebase$ git rebase --onto A 655c38e3cee8 B
Successfully rebased and updated refs/heads/B.
alx@debian:~/tmp/brebase$ git rebase --onto A 655c38e3cee8 C
Successfully rebased and updated refs/heads/C.
alx@debian:~/tmp/brebase$ git log --all --graph --oneline
* 4a4ba76f55a4 (HEAD -> C) bar l
* 86350e1490f3 bar k
| * 4b6b40b14255 (B) foo j
| * ba5a233ee4bc bar i
|/
* 0954f3d9b9e1 (A) bar h
* 4f09c21bf2ca bar g
|\
| * 2a4fa7fe2f44 bar e
* | e42246e75159 baz f
|/
| * ada8aff4f08a (r/B) foo j
| * d6163efdc2db bar i
| | * 450f3a7f4f25 (r/HEAD, r/C) bar l
| | * f7309b21ebfa bar k
| |/
| * e949e24ba457 (r/A) bar h
| * 607b450498be bar g
| |\
| | * b787bcd373d9 bar e
| * | c496b325576f baz f
| |/
| | * dfd9156d099a (r/main, main) foo d
| |/
|/|
* | 4940c7d739be bar c
* | cebc8fde25bb foo b
|/
* 1dcb901ebf60 foo a
alx@debian:~/tmp/brebase$ git switch A
Switched to branch 'A'
alx@debian:~/tmp/brebase$ git brebase --rebase-merges main
Rebase: success
alx@debian:~/tmp/brebase$ git log --all --graph --oneline
* 30e2d96b3da5 (HEAD -> A) bar h
* 01702a5b5d6b bar g
|\
| * c961883d543a bar e
* | e17aadb725c4 baz f
|/
* dfd9156d099a (r/main, main) foo d
| * 4a4ba76f55a4 (C) bar l
| * 86350e1490f3 bar k
| | * 4b6b40b14255 (B) foo j
| | * ba5a233ee4bc bar i
| |/
| * 0954f3d9b9e1 bar h
| * 4f09c21bf2ca bar g
| |\
| | * 2a4fa7fe2f44 bar e
| |/
|/|
| * e42246e75159 baz f
|/
* 4940c7d739be bar c
* cebc8fde25bb foo b
| * ada8aff4f08a (r/B) foo j
| * d6163efdc2db bar i
| | * 450f3a7f4f25 (r/HEAD, r/C) bar l
| | * f7309b21ebfa bar k
| |/
| * e949e24ba457 (r/A) bar h
| * 607b450498be bar g
| |\
| | * b787bcd373d9 bar e
| |/
|/|
| * c496b325576f baz f
|/
* 1dcb901ebf60 foo a
alx@debian:~/tmp/brebase$ git rebase --onto A 0954f3d9b9e1 C
Successfully rebased and updated refs/heads/C.
alx@debian:~/tmp/brebase$ git rebase --onto A 0954f3d9b9e1 B
Auto-merging foo
CONFLICT (content): Merge conflict in foo
error: could not apply 4b6b40b14255... foo j
hint: Resolve all conflicts manually, mark them as resolved with
hint: "git add/rm <conflicted_files>", then run "git rebase --continue".
hint: You can instead skip this commit: run "git rebase --skip".
hint: To abort and get back to the state before "git rebase", run "git rebase --abort".
hint: Disable this message with "git config set advice.mergeConflict false"
Could not apply 4b6b40b14255... # foo j
alx@debian:~/tmp/brebase$ git rebase --abort
alx@debian:~/tmp/brebase$ git switch B
Already on 'B'
Your branch and 'r/B' have diverged,
and have 8 and 6 different commits each, respectively.
(use "git pull" if you want to integrate the remote branch with yours)
alx@debian:~/tmp/brebase$ git brebase A
Rebase: conflict
Bisecting: 2 revisions left to test after this (roughly 1 step)
[c961883d543a2393aacfd6a8345e1d29e6857f7f] bar e
running '.git/bisect-rebase/git-bisect-run-callback'
Rebase: conflict
Bisecting: 0 revisions left to test after this (roughly 0 steps)
[dfd9156d099ad3507a2850294c7a584b80712f04] foo d
running '.git/bisect-rebase/git-bisect-run-callback'
Rebase: conflict
dfd9156d099ad3507a2850294c7a584b80712f04 is the first 'bad' commit
commit dfd9156d099ad3507a2850294c7a584b80712f04
Author: Alejandro Colomar <alx@kernel.org>
Date: 2026-10-05 14:42:50 +0200
foo d
foo | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
bisect found first 'bad' commit
Auto-merging foo
CONFLICT (content): Merge conflict in foo
error: could not apply 4b6b40b14255... foo j
hint: Resolve all conflicts manually, mark them as resolved with
hint: "git add/rm <conflicted_files>", then run "git rebase --continue".
hint: You can instead skip this commit: run "git rebase --skip".
hint: To abort and get back to the state before "git rebase", run "git rebase --abort".
hint: Disable this message with "git config set advice.mergeConflict false"
Could not apply 4b6b40b14255... # foo j
alx@debian:~/tmp/brebase$ echo j >foo
alx@debian:~/tmp/brebase$ git add foo
alx@debian:~/tmp/brebase$ git rebase --continue
[detached HEAD e7fdf07fd077] foo j
1 file changed, 1 insertion(+), 1 deletion(-)
Successfully rebased and updated refs/heads/B.
alx@debian:~/tmp/brebase$ git log --all --graph --oneline
* e7fdf07fd077 (HEAD -> B) foo j
* dddf632a735f bar i
* 7ac284de12ba bar h
* e4541508ab3e bar e
* cefec5878c67 baz f
| * 6c7952d6fec5 (C) bar l
| * bd43684f73c8 bar k
| * 30e2d96b3da5 (A) bar h
| * 01702a5b5d6b bar g
| |\
| | * c961883d543a bar e
| |/
|/|
| * e17aadb725c4 baz f
|/
* dfd9156d099a (r/main, main) foo d
* 4940c7d739be bar c
* cebc8fde25bb foo b
| * ada8aff4f08a (r/B) foo j
| * d6163efdc2db bar i
| | * 450f3a7f4f25 (r/HEAD, r/C) bar l
| | * f7309b21ebfa bar k
| |/
| * e949e24ba457 (r/A) bar h
| * 607b450498be bar g
| |\
| | * b787bcd373d9 bar e
| |/
|/|
| * c496b325576f baz f
|/
* 1dcb901ebf60 foo a
alx@debian:~/tmp/brebase$ git brebase A
Rebase: success
alx@debian:~/tmp/brebase$ git log --all --graph --oneline
* 1201c4f20b19 (HEAD -> B) foo j
* 44103f51a783 bar i
| * 6c7952d6fec5 (C) bar l
| * bd43684f73c8 bar k
|/
* 30e2d96b3da5 (A) bar h
* 01702a5b5d6b bar g
|\
| * c961883d543a bar e
* | e17aadb725c4 baz f
|/
* dfd9156d099a (r/main, main) foo d
* 4940c7d739be bar c
* cebc8fde25bb foo b
| * ada8aff4f08a (r/B) foo j
| * d6163efdc2db bar i
| | * 450f3a7f4f25 (r/HEAD, r/C) bar l
| | * f7309b21ebfa bar k
| |/
| * e949e24ba457 (r/A) bar h
| * 607b450498be bar g
| |\
| | * b787bcd373d9 bar e
| |/
|/|
| * c496b325576f baz f
|/
* 1dcb901ebf60 foo a
This would be impossible with an approach that handles all the way until
the end. I need to be able to stop a bisect-rebase operation on one
branch in the middle, then do a bisect-rebase on its descendants, then
come back to bisect-rebase the parent branch. Does this make sense?
Have a lovely day!
Alex
>
> Thanks
>
> Phillip
>
>
> > That's of course more involved though, so I understand in case you're
> > not interested in doing that.
> >
> > > If not, I will likely provide it in the man-pages repository as a help
> > > tool (which might end up packed by distros as part of manpages-utils).
> > > Is that okay to you? (I ask mainly because it's using the git-
> > > namespace for commands, so you should at lease be aware of it.)
> >
> > I mean overall this is our primary way of extension, by picking up
> > utilities that have the "git-" prefix. So arguably you don't have to ask
> > us for permission to do that.
> >
> > Whether it makes sense to distribute such a tool as part of
> > manpages-utils is a different question, and one where I myself am of a
> > split mind. But that feels more like a question for distributors rather
> > than for us in the Git project.
> >
> > Thanks!
> >
> > Patrick
>
--
<https://www.alejandro-colomar.es>
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next prev parent reply other threads:[~2026-10-05 13:28 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-01 11:58 git-rebase-walk Alejandro Colomar
2026-10-01 13:22 ` git-rebase-walk Patrick Steinhardt
2026-10-01 15:51 ` git-rebase-walk Alejandro Colomar
2026-10-02 6:46 ` git-rebase-walk Patrick Steinhardt
2026-10-02 7:19 ` git-rebase-walk Alejandro Colomar
2026-10-03 19:37 ` git-rebase-walk Nico Williams
2026-10-04 10:03 ` git-rebase-walk Phillip Wood
2026-10-05 13:28 ` Alejandro Colomar [this message]
2026-10-05 13:37 ` git-rebase-walk Alejandro Colomar
2026-10-06 14:01 ` git-rebase-walk Phillip Wood
2026-10-06 14:58 ` git-rebase-walk Nico Williams
2026-10-06 16:45 ` git-rebase-walk Alejandro Colomar
2026-10-08 22:05 ` git-rebase-walk Alejandro Colomar
2026-10-08 22:07 ` git-rebase-walk Alejandro Colomar
2026-10-01 17:31 ` git-rebase-walk Junio C Hamano
2026-10-01 16:10 ` git-rebase-walk Nico Williams
2026-10-01 16:50 ` git-rebase-walk Alejandro Colomar
2026-10-01 17:40 ` git-rebase-walk Nico Williams
2026-10-01 20:29 ` git-rebase-walk Alejandro Colomar
2026-10-01 21:01 ` git-rebase-walk Nico Williams
2026-10-01 21:35 ` git-rebase-walk Nico Williams
2026-10-02 2:49 ` git-rebase-walk Simon Richter
2026-10-02 3:19 ` git-rebase-walk Nico Williams
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