# Introduction

Welcome to git-buildpackage (short gbp), a system that integrates the Debian package build system with Git. The most recent version of this manual can be found here.

This is what gbp can do for you:

- Initially import an existing Debian™ package into Git™

- Incrementally import new versions of a Debian package into Git™ e.g. for importing NMUs or to maintain downstream modifications

- Import new upstream versions from tarballs with optionally filters applied

- Recreate the upstream tarball from information stored in Git™

- Maintain a consistent branch and tag naming within a Git™ repository, across repositories or across a team of developers

- Automatically sign generated tags

- Make sure you have committed all changes to the right branch before building and releasing

- Execute hooks at various points of the package build process e.g. to automatically push changes to remote repositories

- Integrate the build process with cowbuilder or other builders

- Export to a clean build area before building the package

- Generate debian/changelog automatically

- Manage your quilt patches when using 3.0 (quilt) source format

All of this is (hopefully) being done without restricting the user to certain usage patterns.

## Repository Layout and Terminology

It is recommended to have the Debian™ packaging on a separate branch than the upstream source [1]. This is necessary to be able to import and merge in new upstream versions via gbp import-orig. To distinguish these two branches, the following terminology [2] is used:

- The `debian-branch` (the default branch name used in the Git™ repository is master) holds your current development work. That's the branch you usually cut your releases from and the default branch new upstream releases are merged onto.

- The `upstream-branch` (the default branch name used in the Git™ repository is upstream) holds the upstream releases. This can either be a branch you import to or a branch of an upstream Git™ repository you pull from.

- The `pristine-tar branch` (the default branch name used in the Git™ repository is pristine-tar) holds the necessary additional information to recreate the original tarball from the `upstream-branch`. In order to use this feature, you need to install the pristine-tar™ package.

- There can be one or more `patch-queue` branches. Every patch-queue branch is related to a `debian-branch`. If the `debian-branch` is called master, the corresponding patch-queue branch is called patch-queue/master. The patch-queue branch is the Debian™ branch plus the contents of debian/patches applied. These branches are managed with gbp pq.

You're completely free to pick any repository layout; the branch names above are only gbp's defaults. They can be changed at any point in time, and you can work with an arbitrary number of branches. For example, branches like nmu, backports or stable might (temporarily or permanently) become your `debian-branch`, and branches like dfsg or snapshots might become your `upstream-branch`—it doesn't matter if these branches are maintained with gbp import-orig or not.

A recommended branch layout is described in the section called “Branch layout”.

Since gbp buildpackage only works with local Git™-repositories, you have to use git push in order to publish your changes to remote repositories like git.debian.org; this can be automated with gbp buildpackage's `post-tag` hook.

[1] this, of course, has no meaning for Debian™ native packages

[2] corresponding to the command line and config file options