Building topgit for Debian
--------------------------

The topgit source package  uses quilt to apply and remove its patches. Please
refer to /usr/share/doc/quilt/README.source for information about how to use
quilt for source packages.

The quilt series is, however, generated from the Git repository, using TopGit
itself. While subject to change, this currently happens as follows:

1. Branches in use
~~~~~~~~~~~~~~~~~~
The following branches are in use in the package:

- upstream: tracks the upstream Git repository
- fixes/*: patches fixing problems with upstream
- features/*: patches providing new features, targetted upstream
- master: the main Debianisation branch
- debian/*: Debian-specific patches

upstream and master are regular Git branches, while the others are TopGit
branches. The reason why master is not a TopGit branch itself is so that it's
possible to export all TopGit-managed branches into the quilt series, without
having to make an exception for master.

2. Developing a new feature
~~~~~~~~~~~~~~~~~~~~~~~~~~~
If you want to develop a new feature (or bug fix), first consider whether the
patch is intended to go upstream or is a Debian-specific change. Choose the
namespace accordingly and base it off upstream or master respectively. If the
patch depends on another patch, obviously base it off the respective TopGit
branch.

The following are the steps required to add a feature branch/patch:

1. tg create features/new-feature upstream
   - or -
   tg create debian/new-debian-stuff master

2. edit .topmsg and make the subject line be a short description, optionally
   add a longer description to the body

3. git add .topmsg && git commit -m'create branch features/new-feature'

3. Obtaining the upstream tarball
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The upstream tarball for $VERSION can be obtained using pristine-tar:

  pristine-tar checkout ../topgit_$VERSION.orig.tar.gz

4. Building the package
~~~~~~~~~~~~~~~~~~~~~~~
To build the package, you check out the build branch, recreate debian/patches,
commit, build, test, upload, tag:

 1. git checkout build && git rm -r debian/patches
 2. tg create stage-0.2-1 fixes/destdir debian/locations ...
 3. git commit -m'staging 0.2-1'
 4. tg export --quilt debian/patches
 5. rm debian/patches/stage-*
 6. sed -i '/^stage-/d' debian/patches/series
 7. git checkout -f build && git add debian/patches
 8. git commit -m'preparing 0.2-1'
 9. build, test, upload, tag ('debian/topgit-0.2-1')
10. tg delete stage-0.2-1

This process is still very cumbersome and needs to be improved, ideally within
TopGit.

5. Importing a new upstream version
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To import a new upstream, pull it into the upstream branch, merge upstream
into the master branch, ideally together with an update to debian/changelog,
then update all TopGit branches:

1. git checkout upstream
2. git pull
3. git checkout master
4. git merge upstream
5. tg summary
6. for every branch that is prefixed with 'D' in the output:
     git checkout $BRANCH && tg update

6. Building an upstream tarball
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Until upstream provides official tarballs, the following can be used to create
them for Debian:

1. git archive --prefix=$(git describe upstream)/ --verbose upstream \
    | gzip -9 > ../$(git describe upstream | sed s,-,_,).orig.tar.gz
2. pristine-tar commit ../$(git describe upstream | sed s,-,_,).orig.tar.gz \
    upstream

All comments and suggestions are welcome, especially those pertaining to
auto-generating debian/changelog from commit logs.

 -- martin f. krafft <madduck@debian.org>  Mon, 11 Aug 2008 17:32:48 -0300