Git Internals
Rebase internals and the sequencer
Understand rebase as commit replay managed by the sequencer, making conflict handling and recovery decisions more predictable.
- Readers building a durable Git mental model
- Developers who keep running into history, ref, or recovery confusion
- Comfort reading basic Git output
- A rough idea of commits, branches, and HEAD
- Learning low-level terms without connecting them to commands
- Collapsing objects, refs, and working state into one concept
Data & Performance
- replayeach replayed commit gets a new SHA because its parent changed — history is rewritten, not movedSource: git-rebase(1) official manual
Key Quotes
Rebase works by replaying each commit from the branch being rebased onto the new base, producing new commits with different hashes but the same changes.
Citations & Further Reading
- Git rebase [Official]
- Git cherry pick [Official]
- Git reflog [Official]
What you will learn
- Understand the core purpose of Rebase internals and the sequencer
- Master the basic usage and common options of Rebase internals and the sequencer
- Understand rebase as commit replay managed by the sequencer, making conflict handling and recovery decisions more predictable.
- Understand key concepts: What the sequencer does
- Know when to use this feature and when to avoid it
Rebase is ordered commit replay. The sequencer coordinates replay state and pause/resume behavior.
Start with a problem
You use Git commands daily, but occasionally encounter 'strange' behavior — like being told a file changed when you didn't touch it, or unexpected conflicts during a rebase. You want to understand how Git works under the hood.
What the sequencer does
- computes replay set
- applies commits onto new base in order
- pauses on conflict
- resumes until queue is complete
Why commit IDs change
Replayed commits are new objects with potentially different parents and metadata.
Meaning of --continue, --skip, --abort
continue: proceed with replay queueskip: drop current queued commitabort: discard replay and return to start point
Recovery-first pattern
Before experimenting further:
git reflog
git switch -c rescue/pre-rebase HEAD@{n}
Skipping blindly can silently lose meaningful patches. Decide commit-by-commit why skip is safe.
Good follow-up reads
Try it yourself
- Practice the rebase-internals-and-sequencer command in a test repository and observe state changes before and after
- Experiment with different options and compare the output differences
- Simulate a real scenario where you would need to use this, and walk through the full process
Further reading
Keep going on the same topic: