non-native Debian package using B<dgit>. We maintain the Debian delta
as a series of git commits on our master branch. We use
git-debrebase(1) to shuffle our branch such that this series of git
-commits appears at the end of the branch. This does not involve
-rewriting any public git history.
+commits appears at the end of the branch. All the public git history
+is fast-forwarding, i.e., we do not rewrite and force-push.
Some advantages of this workflow:
=item
-Manipulate the patch queue using the full power of git-rebase(1),
-instead of relying on quilt(1), and without having to switch away to
-another branch, as with gbp-pq(1).
+Manipulate the delta queue using the full power of git-rebase(1),
+instead of relying on quilt(1), and without having to switch back and
+forth between patches-applied and patches-unapplied branches when
+committing changes and trying to build, as with gbp-pq(1).
+
+=item
+
+If you are using 3.0 (quilt), provide your delta queue as a properly
+separated series of quilt patches in the source package that you
+upload to the archive (unlike with dgit-maint-merge(7)).
=item
where it can benefit downstream dgit users, such as people using dgit
to do an NMU (see dgit-nmu-simple(7) and dgit-user(7)).
+=item
+
+Minimise the amount you need to know about 3.0 (quilt) in order to
+maintain Debian source packages which use that format.
+
=back
This workflow is appropriate for packages where the Debian delta
contains multiple pieces which interact, or which you don't expect to
be able to upstream soon. For packages with simple and/or short-lived
-Debian deltas, use of git-debrebase(1) might introduce unneeded
-complexity. For such packages, consider the workflow described in
+Debian deltas, use of git-debrebase(1) introduces unneeded complexity.
+For such packages, consider the workflow described in
dgit-maint-merge(7).
=head1 INITIAL DEBIANISATION
-=head2 When upstream tags releases in git
-
This section explains how to start using this workflow with a new
package. It should be skipped when converting an existing package to
this workflow.
+=head2 When upstream tags releases in git
+
Suppose that the latest stable upstream release is 1.2.2, and this has
been tagged '1.2.2' by upstream.
=back
-Now go ahead and Debianise your package. Just make commits on the
-master branch, adding things in the I<debian/> directory. If you need
-to patch the upstream source, see "EDITING THE PATCH QUEUE", below.
-Note that there is no need to maintain a separate 'upstream' branch,
-unless you also happen to be involved in upstream development. We
-work with upstream tags rather than any branches, except when
-forwarding patches (see FORWARDING PATCHES UPSTREAM, below).
+Now go ahead and Debianise your package. Make commits on the master
+branch, adding things in the I<debian/> directory, or patching the
+upstream source. For technical reasons, B<it is essential that your
+first commit introduces the debian/ directory containing at least one
+file, and does nothing else.> In other words, make a commit
+introducing I<debian/> before patching the upstream source.
Finally, you need an orig tarball:
=back
You are now ready to proceed as above, making commits to the
-I<debian/> directory.
+I<debian/> directory and to the upstream source. As above, for
+technical reasons, B<it is essential that your first commit introduces
+the debian/ directory containing at least one file, and does nothing
+else.> In other words, make a commit introducing I<debian/> before
+patching the upstream source.
+
=head1 CONVERTING AN EXISTING PACKAGE
=back
If your tree is patches-unapplied, you will need to make a commit
-corresponding to each of the quilt patches. gbp-pq(1) can do this for
-us:
+corresponding to each of the quilt patches. You can use
+
+=over 4
+
+ git debrebase convert-from-gbp
+
+=back
+
+or manually with gbp-pq(1):
=over 4
I<debian/source/local-options>. One way to have dgit check your
progress is to run B<dgit build-source>.
-The first dgit push will require I<--overwrite>. If this is the first
-ever dgit push of the package, consider passing
-I<--deliberately-not-fast-forward> instead of I<--overwrite>. This
-avoids introducing a new origin commit into your git history. (This
-origin commit would represent the most recent non-dgit upload of the
-package, but this should already be represented in your git history.)
+The first dgit push will require I<--overwrite>.
+
+=head1 GIT CONFIGURATION
+
+This workflow does not support using B<git merge> to merge divergent
+branches of development (see "OTHER MERGES" in git-debrebase(5)). You
+should configure git such that B<git pull> does not try to merge:
+
+=over 4
+
+ % git config --local pull.rebase true
+
+=back
+
+Now when you pull work from other Debian contributors, git will rebase
+your work on top of theirs.
+
+If you use this repository for upstream development in addition to
+Debian packaging work, you may not want to set this global setting.
+Instead, see the B<branch.autoSetupRebase> and
+B<branch.E<lt>nameE<gt>.rebase> settings in git-config(5).
=head1 IMPORTING NEW UPSTREAM RELEASES
+There are two steps: obtaining git refs that correspond to the new
+release, and importing that release using git-debrebase(1).
+
=head2 Obtaining the release
=head3 When upstream tags releases in git
=back
-=head1 EDITING THE PATCH QUEUE
+=head1 EDITING THE DELTA QUEUE
=head2 Adding new patches
=back
to start an interactive rebase. You can edit, re-order and delete
-commits just as you would during B<git rebase -i>. Alternatively, you
-can perform a non-interactive rebase like this:
-
-=over 4
-
- % git debrebase -- [git-rebase options...]
-
-=back
-
-For example,
-
-=over 4
-
- % git debrebase -- --autosquash
-
-=back
-
-A third alternative is to have git-debrebase(1) shuffle all the Debian
-changes to the end of your branch, and then manipulate them yourself
-using git-rebase(1). For example,
-
-=over 4
-
- % git debrebase launder
- % git rebase -i HEAD^5 # there are 4 Debian patches
-
-=back
+commits just as you would during B<git rebase -i>.
=head2 Editing patches: finishing a debrebase
=over 4
- % git debrebase stitch
+ % git debrebase conclude
=back
-Note that each time you stitch a debrebase you introduce a pseudomerge
-into your git history, which may make it harder to read. Try to do
-all of the editing of the patch queue that you think will be needed
-for this upload in a single debrebase, so that there is a single
-debrebase stitch.
-
-A strategy is to debrebase only right before you upload. Before that
-point, instead of editing the existing patch series, you append fixup
-commits (and reversions of commits) that alter the upstream source to
-the required state. You can freely push and pull from
-B<salsa.debian.org> during this. Just before uploading, you debrebase
-to tidy everything up.
+Note that each time you conclude a debrebase you introduce a
+pseudomerge into your git history, which may make it harder to read.
+Try to do all of the editing of the delta queue that you think will be
+needed for this upload in a single debrebase, so that there is a
+single debrebase stitch.
=head1 BUILDING AND UPLOADING
-Use B<dgit build>, B<dgit sbuild>, B<dgit push> and B<dgit
-push-source> as detailed in dgit(1). If any command fails, dgit will
-provide a carefully-worded error message explaining what you should
-do. If it's not clear, file a bug against dgit. Remember to pass
-I<--new> for the first upload.
-
-After dgit pushing, be sure to git push to B<salsa.debian.org>, if
-you're using that.
-
-As an alternative to B<dgit build> and friends, you can use a tool
-like gitpkg(1). This works because like dgit, gitpkg(1) enforces that
-HEAD has exactly the contents of the source package. gitpkg(1) is
-highly configurable, and one dgit user reports using it to produce and
-test multiple source packages, from different branches corresponding
-to each of the current Debian suites.
-
-If you want to skip dgit's checks while iterating on a problem with
-the package build (for example, you don't want to commit your changes
-to git), you can just run dpkg-buildpackage(1) or debuild(1) instead.
+You can use dpkg-buildpackage(1) for test builds. When you are ready
+to build for an upload, use B<dgit sbuild>.
-=head2 Laundering the patch queue before uploading
+Upload with B<dgit push> or B<dgit push-source>. Remember to pass
+I<--new> if the package is new in the target suite.
-Just before you B<dgit push> or B<dgit push-source>, you might want to
-have git-debrebase(1) shuffle your branch such that the Debian patch
-queue appears at the end:
+Right before uploading, if you did not just already do so, you might
+want to have git-debrebase(1) shuffle your branch such that the Debian
+delta queue appears right at the tip of the branch you will push:
=over 4
Note that this will introduce a new pseudomerge.
+After dgit pushing, be sure to git push to B<salsa.debian.org>, if
+you're using that.
+
=head1 HANDLING DFSG-NON-FREE MATERIAL
+This covers only DFSG-non-free material. Material which is legally
+dangerous (for example, files which are actually illegal) cannot be
+handled this way.
+
+If you encounter possibly-legally-dangerous material in the upstream
+source code you should seek advice. It is often best not to make a
+fuss on a public mailing list (at least, not at first). Instead,
+email your archive administrators. For Debian that is
+ To: dgit-owner@debian.org, ftpmaster@ftp-master.debian.org
+
=head2 When upstream tags releases in git
We create a DFSG-clean tag to import to master:
=back
-Before invoking B<git debrebase new-upstream-v0>, you should first
-determine whether it would be legally dangerous for the non-free
-material to be publicly accessible in the git history on
-B<dgit-repos>.
-
-If it would be dangerous, there is a big problem;
-in this case please consult your archive administrators
-(for Debian this is the dgit administrator dgit-owner@debian.org
-and the ftpmasters ftpmaster@ftp-master.debian.org).
-
=head2 When upstream releases only tarballs
The easiest way to handle this is to add a B<Files-Excluded> field to
I<debian/watch>. See uscan(1). Alternatively, see the I<--filter>
option detailed in gbp-import-orig(1).
-=head1 FORWARDING PATCHES UPSTREAM
+=head1 INCORPORATING NMUS
-The basic steps are:
+In the simplest case,
=over 4
-=item 1.
+ % dgit fetch
+ % git merge --ff-only dgit/dgit/sid
+
+=back
+
+If that fails, because your branch and the NMUers work represent
+divergent branches of development, you have a number of options. Here
+we describe the two simplest.
+
+=head2 Rebasing your work onto the NMU
+
+=over 4
+
+ % git rebase dgit/dgit/sid
+
+=back
+
+If the NMUer added new commits modifying the upstream source, you will
+probably want to debrebase before your next upload to tidy those up.
+
+For example, the NMUer might have used git-revert(1) to unapply one of
+your patches. A debrebase will strip both the patch and the reversion
+from the delta queue.
+
+=head2 Manually applying the debdiff
+
+If you cannot rebase because you have already pushed to
+B<salsa.debian.org>, say, you can manually apply the NMU debdiff,
+commit and debrebase. The next B<dgit push> will require
+I<--overwrite>.
+
+=head1 HINTS AND TIPS
+
+=head2 Minimising pseudomerges
+
+Above we noted that each time you conclude a debrebase, you introduce
+a pseudomerge into your git history, which may make it harder to read.
+
+A convention you can use to minimise the number of pseudomerges is to
+debrebase only right before you upload.
+
+Before that point, instead of editing the existing delta queue, you
+append fixup commits (and reversions of commits) that alter the
+upstream source to the required state. You can freely push and pull
+from B<salsa.debian.org> during this. Just before uploading, you
+debrebase, once, to tidy everything up.
-Create a new branch based off upstream's master branch.
+=head2 Upstream branches
-=item 2.
+Except in the case where upstream releases only tarballs, we do not
+maintain a separate 'upstream' branch (unless you also happen to be
+involved in upstream development). We work with upstream tags rather
+than any branches, except temporary branches used to prepare patches
+for forwarding upstream, for example.
-git-cherry-pick(1) commits from your master branch onto your new
-branch.
+The thought behind this is that branches are things to which one
+expects to commit, while tags are immutable points in history. From
+the Debian point of the view, the upstream source is immutable. It's
+our packaging to which we expect to commit.
-=item 3.
+=head2 The first ever dgit push
-Push the branch somewhere and ask upstream to merge it, or use
-git-format-patch(1) or git-request-pull(1).
+If this is the first ever dgit push of the package, consider passing
+I<--deliberately-not-fast-forward> instead of I<--overwrite>. This
+avoids introducing a new origin commit into your git history. (This
+origin commit would represent the most recent non-dgit upload of the
+package, but this should already be represented in your git history.)
+
+=head2 Alternative ways to start a debrebase
+
+Above we started an interactive debrebase by invoking git-debrebase(1)
+without any arguments, i.e.
+
+=over 4
+
+ % git debrebase
=back
-For example (and it is only an example):
+It is also possible to perform a non-interactive rebase, like this:
=over 4
- % # fork foo.git on GitHub
- % git remote add -f fork git@github.com:spwhitton/foo.git
- % git checkout -b fix-error upstream/master
- % git config branch.fix-error.pushRemote fork
- % git cherry-pick master^2
- % git push
- % # submit pull request on GitHub
+ % git debrebase -- [git-rebase options...]
=back
-Note that when you merge an upstream release containing your forwarded
-patches, a debrebase will transparently handle "dropping" the patches
-that have been forwarded, "retaining" the ones that haven't.
-=head1 INCORPORATING NMUS
+A third alternative is to have git-debrebase(1) shuffle all the Debian
+changes to the end of your branch, and then manipulate them yourself
+using git-rebase(1) directly. For example,
=over 4
- % dgit pull
+ % git debrebase launder
+ % git rebase -i HEAD~5 # there are 4 Debian patches
=back
-If the NMUer added new commits modifying the upstream source, you will
-probably want to debrebase before your next upload to tidy those up.
-
-For example, the NMUer might have used git-revert(1) to unapply one of
-your patches. A debrebase will strip both the patch and the reversion
-from the patch series.
+If you take this approach, you should be very careful not to start the
+rebase earlier than the beginning of the delta queue.
=head1 SEE ALSO
~ianmdlvl / dgit.git / blobdiff