git rebase --exec Explained - Run Your Tests on Every Commit Before You Push, with Real Output, the Failure Path, and the Three Things That Bit Me

Mon, 26 Oct 2026 00:00:00 +0000

TL;DR

git rebase --exec "<cmd>" <upstream> (short form -x) appends an exec <cmd> line after every pick in the rebase instruction list, so the command runs in the working tree of each replayed commit. A non-zero exit stops the rebase on that commit with exit code 1.
When it stops, fix the commit in place: edit, git commit --amend --no-edit -a, then git rebase --continue. Every commit from the fixed one onward gets a new hash; commits that passed unchanged keep theirs.
Fixing a commit can conflict with the next one. In my run the amended line was the context the following commit appended to, so --continue hit a merge conflict I had to resolve before the exec ran again.
--reschedule-failed-exec re-runs the failed command on every --continue until it passes, instead of moving on. Set it permanently with git config rebase.rescheduleFailedExec true.
An empty range runs nothing and still prints Successfully rebased. Check git log --oneline <upstream>..HEAD first.
Not your exact case? If you want to find which commit introduced a bug rather than test all of them, that is git bisect run; and if you are new to rebasing, start with my free Git and GitHub course.

Table of Content

What exec does inside a rebase
The lab repository
A clean run over every commit
A run that stops on a bad commit, and the fix
reschedule-failed-exec: retry instead of skipping
More than one command, and seeing which commit is running
exec versus bisect run versus CI
What broke when I ran this
Conclusion

1. What exec does inside a rebase

Most people meet exec as one of the commands in the interactive rebase instruction list, next to pick, squash and drop. The git rebase reference describes the --exec <cmd> option as appending exec <cmd> after each line that creates a commit in the final history, and says that any command that fails will interrupt the rebase with exit code 1. It also says it uses the interactive machinery internally but can be run without --interactive, which is the form I use most: no editor opens, the commands just run.

Git on Jhooq

git rebase --exec Explained - Run Your Tests on Every Commit Before You Push, with Real Output, the Failure Path, and the Three Things That Bit Me

TL;DR

Table of Content

1. What exec does inside a rebase