1dgit-maint-debrebase(7) dgit dgit-maint-debrebase(7)
2
6 dgit - tutorial for package maintainers, using a workflow centered
7 around git-debrebase(1)
8
10 This document describes elements of a workflow for maintaining a non-
11 native Debian package using dgit. We maintain the Debian delta as a
12 series of git commits on our master branch. We use git-debrebase(1) to
13 shuffle our branch such that this series of git commits appears at the
14 end of the branch. All the public git history is fast-forwarding,
15 i.e., we do not rewrite and force-push.
16 Some advantages of this workflow:
18 • Manipulate the delta queue using the full power of git-rebase(1),
20 instead of relying on quilt(1), and without having to switch back
21 and forth between patches-applied and patches-unapplied branches
22 when committing changes and trying to build, as with gbp-pq(1).
23 • If you are using 3.0 (quilt), provide your delta queue as a
25 properly separated series of quilt patches in the source package
26 that you upload to the archive (unlike with dgit-maint-merge(7)).
27 • Avoid the git tree being dirtied by the application or
29 unapplication of patches, as they are always applied.
30 • Benefit from dgit's safety catches. In particular, ensure that
32 your upload always matches exactly your git HEAD.
33 • Provide your full git history in a standard format on dgit-repos,
35 where it can benefit downstream dgit users, such as people using
36 dgit to do an NMU (see dgit-nmu-simple(7) and dgit-user(7)).
37 • Minimise the amount you need to know about 3.0 (quilt) in order to
39 maintain Debian source packages which use that format.
40 This workflow is appropriate for packages where the Debian delta
42 contains multiple pieces which interact, or which you don't expect to
43 be able to upstream soon. For packages with simple and/or short-lived
44 Debian deltas, use of git-debrebase(1) introduces unneeded complexity.
45 For such packages, consider the workflow described in
46 dgit-maint-merge(7).
47
49 This section explains how to start using this workflow with a new
50 package. It should be skipped when converting an existing package to
51 this workflow.
52 When upstream tags releases in git
54 Suppose that the latest stable upstream release is 1.2.2, and this has
55 been tagged '1.2.2' by upstream.
56 % git clone -oupstream https://some.upstream/foo.git
58 % cd foo
59 % git verify-tag 1.2.2
60 % git reset --hard 1.2.2
61 % git branch --unset-upstream
62 The final command detaches your master branch from the upstream remote,
64 so that git doesn't try to push anything there, or merge unreleased
65 upstream commits. To maintain a copy of your packaging branch on
66 salsa.debian.org in addition to dgit-repos, you can do something like
67 this:
68 % git remote add -f origin salsa.debian.org:Debian/foo.git
70 % git push --follow-tags -u origin master
71 Now go ahead and Debianise your package. Make commits on the master
73 branch, adding things in the debian/ directory, or patching the
74 upstream source. For technical reasons, it is essential that your
75 first commit introduces the debian/ directory containing at least one
76 file, and does nothing else. In other words, make a commit introducing
77 debian/ before patching the upstream source.
78 Finally, you need an orig tarball:
80 % git deborig
82 See git-deborig(1) if this fails.
84 This tarball is ephemeral and easily regenerated, so we don't commit it
86 anywhere (e.g. with tools like pristine-tar(1)).
87 Comparing upstream's tarball releases
89 The above assumes that you know how to build the package from git
91 and that doing so is straightforward.
92 If, as a user of the upstream source, you usually build from
94 upstream tarball releases, rather than upstream git tags, you will
95 sometimes find that the git tree doesn't contain everything that is
96 in the tarball.
97 Additional build steps may be needed. For example, you may need
99 your debian/rules to run autotools.
100 You can compare the upstream tarball release, and upstream git tag,
102 within git, by importing the tarball into git as described in the
103 next section, using a different value for 'upstream-tag', and then
104 using git-diff(1) to compare the imported tarball to the release
105 tag.
106 Using untagged upstream commits
108 Sometimes upstream does not tag their releases, or you want to
110 package an unreleased git snapshot. In such a case you can create
111 your own upstream release tag, of the form upstream/ver, where ver
112 is the upstream version you plan to put in debian/changelog. The
113 upstream/ prefix ensures that your tag will not clash with any tags
114 upstream later creates.
115 For example, suppose that the latest upstream release is 1.2.2 and
117 you want to package git commit ab34c21 which was made on
118 2013-12-11. A common convention is to use the upstream version
119 number 1.2.2+git20131211.ab34c21 and so you could use
120 % git tag -s upstream/1.2.2+git20131211.ab34c21 ab34c21
122 to obtain a release tag, and then proceed as above.
124 One can generate such a versioned tag using git show's --pretty
126 option. e.g.:
127 % git tag -s upstream/$(git show --date=format:%Y%m%d --pretty=format:"1.2.2+git%cd.%h" --quiet upstream/main) upstream/main
129 When upstream releases only tarballs
131 Because we want to work in git, we need a virtual upstream branch with
132 virtual release tags. gbp-import-orig(1) can manage this for us. To
133 begin
134 % mkdir foo
136 % cd foo
137 % git init
138 % git checkout -b upstream
139 % gbp import-orig \
140 --upstream-branch=upstream --debian-branch=master \
141 --upstream-tag='upstream/%(version)s' \
142 --sign-tags --no-pristine-tar \
143 ../foo_1.2.2.orig.tar.xz
144 % git branch -f upstream
145 This should leave you on the master branch. Next, our upstream branch
147 cannot be pushed to dgit-repos, but since we will need it whenever we
148 import a new upstream version, we must push it somewhere. The usual
149 choice is salsa.debian.org:
150 % git remote add -f origin salsa.debian.org:Debian/foo.git
152 % git push --follow-tags -u origin master upstream
153 You are now ready to proceed as above, making commits to the debian/
155 directory and to the upstream source. As above, for technical reasons,
156 it is essential that your first commit introduces the debian/ directory
157 containing at least one file, and does nothing else. In other words,
158 make a commit introducing debian/ before patching the upstream source.
159 A convenient way to ensure this requirement is satisfied is to start by
161 creating debian/gbp.conf:
162 [DEFAULT]
164 upstream-branch = upstream
165 debian-branch = master
166 upstream-tag = upstream/%(version)s
167 sign-tags = True
169 pristine-tar = False
170 pristine-tar-commit = False
171 [import-orig]
173 merge = False
174 and commit that:
176 % git add debian/gbp.conf && git commit -m "create gbp.conf"
178 Note that we couldn't create debian/gbp.conf before now for the same
180 technical reasons which require our first commit to introduce debian/
181 without patching the upstream source. That's why we had to pass a lot
182 of options to our first call to gbp-import-orig(1).
183
185 This section explains how to convert an existing Debian package to this
186 workflow. It should be skipped when debianising a new package.
187 If you have an existing git history that you have pushed to an ordinary
189 git server like salsa.debian.org, we start with that. If you don't
190 already have it locally, you'll need to clone it, and obtain the
191 corresponding orig.tar from the archive:
192 % git clone salsa.debian.org:Debian/foo
194 % cd foo
195 % dgit setup-new-tree
196 % origtargz
197 If you don't have any existing git history, or you have history only on
199 the special dgit-repos server, we start with dgit clone:
200 % dgit clone foo
202 % cd foo
203 Then we make new upstream tags available:
205 % git remote add -f upstream https://some.upstream/foo.git
207 We now use a git debrebase convert-from-* command to convert your
209 existing history to the git-debrebase(5) data model. Which command you
210 should use depends on some facts about your repository:
211 (A) There is no delta queue.
213 If there do not exist any Debian patches, use
214 % git debrebase convert-from-gbp
216 (B) There is a delta queue, and patches are unapplied.
218 This is the standard git-buildpackage(1) workflow: there are Debian
219 patches, but the upstream source is committed to git without those
220 patches applied. Use
221 % git debrebase convert-from-gbp
223 If you were not previously using dgit to upload your package (i.e.
225 you were not using the workflow described in dgit-maint-gbp(7)),
226 and you happen to have run dgit fetch sid in this clone of the
227 repository, you will need to pass --fdiverged to this command.
228 (C) There is a delta queue, and patches are applied.
230 Use
231 % git debrebase convert-from-dgit-view
233 Finally, you need to ensure that your git HEAD is dgit-compatible,
235 i.e., it is exactly what you would get if you deleted .git, invoked
236 dpkg-buildpackage -S, and then unpacked the resultant source package.
237 To achieve this, you might need to delete debian/source/local-options.
239 One way to have dgit check your progress is to run dgit build-source.
240
242 git-debrebase(1) does not yet support using git merge to merge
243 divergent branches of development (see "OTHER MERGES" in
244 git-debrebase(5)). You should configure git such that git pull does
245 not try to merge:
246 % git config --local pull.rebase true
248 Now when you pull work from other Debian contributors, git will rebase
250 your work on top of theirs.
251 If you use this clone for upstream development in addition to Debian
253 packaging work, you may not want to set this global setting. Instead,
254 see the branch.autoSetupRebase and branch.<name>.rebase settings in
255 git-config(5).
256
258 There are two steps: obtaining git refs that correspond to the new
259 release, and importing that release using git-debrebase(1).
260 Obtaining the release
262 When upstream tags releases in git
263 % git fetch --tags upstream
265 If you want to package an untagged upstream commit (because upstream
267 does not tag releases or because you want to package an upstream
268 development snapshot), see "Using untagged upstream commits" above.
269 When upstream releases only tarballs
271 You will need the debian/gbp.conf from "When upstream releases only
273 tarballs", above. You will also need your upstream branch. Above, we
274 pushed this to salsa.debian.org. You will need to clone or fetch from
275 there, instead of relying on dgit clone/dgit fetch alone.
276 Then, either
278 % gbp import-orig ../foo_1.2.3.orig.tar.xz
280 or if you have a working watch file
282 % gbp import-orig --uscan
284 Importing the release
286 % git debrebase new-upstream 1.2.3
287 This invocation of git-debrebase(1) involves a git rebase. You may
289 need to resolve conflicts if the Debian delta queue does not apply
290 cleanly to the new upstream source.
291 If all went well, you can now review the merge of the new upstream
293 release:
294 git diff debian/1.2.2-1..HEAD -- . ':!debian'
296 Also, diff with --name-status and --diff-filter=ADR to see just the
298 list of added or removed files, which is useful to determine whether
299 there are any new or deleted files that may need accounting for in your
300 copyright file.
301 If you obtained a tarball from upstream, you are ready to try a build.
303 If you merged a git tag from upstream, you will first need to generate
304 a tarball:
305 % git deborig
307
309 Just make commits on master that change the contents of debian/.
310
312 Adding new patches
313 Adding new patches is straightforward: just make commits touching only
314 files outside of the debian/ directory. You can also use tools like
315 git-revert(1), git-am(1) and git-cherry-pick(1).
316 Editing patches: starting a debrebase
318 git-debrebase(1) is a wrapper around git-rebase(1) which allows us to
319 edit, re-order and delete patches. Run
320 % git debrebase -i
322 to start an interactive rebase. You can edit, re-order and delete
324 commits just as you would during git rebase -i.
325 Editing patches: finishing a debrebase
327 After completing the git rebase, your branch will not be a fast-forward
328 of the git HEAD you had before the rebase. This means that we cannot
329 push the branch anywhere. If you are ready to upload, dgit push-source
330 (or dgit push-built) will take care of fixing this up for you.
331 If you are not yet ready to upload, and want to push your branch to a
333 git remote such as salsa.debian.org,
334 % git debrebase conclude
336 Note that each time you conclude a debrebase you introduce a
338 pseudomerge into your git history, which may make it harder to read.
339 Try to do all of the editing of the delta queue that you think will be
340 needed for this editing session in a single debrebase, so that there is
341 a single debrebase stitch.
342
344 You can use dpkg-buildpackage(1) for test builds. When you are ready
345 to build for an upload, use dgit sbuild, dgit pbuilder or dgit
346 cowbuilder.
347 Upload with dgit push-source or dgit push-built. Remember to pass
349 --new if the package is new in the target suite.
350 In some cases where you used git debrebase convert-from-gbp since the
352 last upload, it is not possible for dgit to make your history fast-
353 forwarding from the history on dgit-repos. In such cases you will have
354 to pass --overwrite to dgit. git-debrebase will normally tell you if
355 this will be needed.
356 If you want to upload with git-debpush(1), for the first upload you
358 should pass the --quilt=linear quilt mode option (see git-debpush(1)).
359 Right before uploading, if you did not just already do so, you might
361 want to have git-debrebase(1) shuffle your branch such that the Debian
362 delta queue appears right at the tip of the branch you will push:
363 % git debrebase
365 % dgit push-source
366 Note that this will introduce a new pseudomerge.
368 After dgit pushing, be sure to git push to salsa.debian.org, if you're
370 using that.
371
373 Illegal material
374 Here we explain how to handle material that is merely DFSG-non-free.
375 Material which is legally dangerous (for example, files which are
376 actually illegal) cannot be handled this way.
377 If you encounter possibly-legally-dangerous material in the upstream
379 source code you should seek advice. It is often best not to make a
380 fuss on a public mailing list (at least, not at first). Instead, email
381 your archive administrators. For Debian that is
382 To: dgit-owner@debian.org, ftpmaster@ftp-master.debian.org
383 DFSG-non-free: When upstream tags releases in git
385 Our approach is to maintain a DFSG-clean upstream branch, and create
386 tags on this branch for each release that we want to import. We then
387 import those tags per "Importing the release", above. In the case of a
388 new package, we base our initial Debianisation on our first DFSG-clean
389 tag.
390 For the first upstream release that requires DFSG filtering:
392 % git checkout -b upstream-dfsg 1.2.3
394 % git rm evil.bin
395 % git commit -m "upstream version 1.2.3 DFSG-cleaned"
396 % git tag -s 1.2.3+dfsg
397 % git checkout master
398 Now either proceed with "Importing the release" on the 1.2.3+dfsg tag,
400 or in the case of a new package,
401 % git branch --unset-upstream
403 % git reset --hard 1.2.3+dfsg
404 and proceed with "INITIAL DEBIANISATION".
406 For subsequent releases (whether or not they require additional
408 filtering):
409 % git checkout upstream-dfsg
411 % git merge 1.2.4
412 % git rm further-evil.bin # if needed
413 % git commit -m "upstream version 1.2.4 DFSG-cleaned" # if needed
414 % git tag -s 1.2.4+dfsg
415 % git checkout master
416 % # proceed with "Importing the release" on 1.2.4+dfsg tag
417 Our upstream-dfsg branch cannot be pushed to dgit-repos, but since we
419 will need it whenever we import a new upstream version, we must push it
420 somewhere. Assuming that you have already set up an origin remote per
421 the above,
422 % git push --follow-tags -u origin master upstream-dfsg
424 DFSG-non-free: When upstream releases only tarballs
426 The easiest way to handle this is to add a Files-Excluded field to
427 debian/copyright, and a uversionmangle setting in debian/watch. See
428 uscan(1). Alternatively, see the --filter option detailed in
429 gbp-import-orig(1).
430
432 In the simplest case,
433 % dgit fetch
435 % git merge --ff-only dgit/dgit/sid
436 If that fails, because your branch and the NMUers' work represent
438 divergent branches of development, you have a number of options. Here
439 we describe the two simplest.
440 Note that you should not try to resolve the divergent branches by
442 editing files in debian/patches. Changes there would either cause
443 trouble, or be overwritten by git-debrebase(1).
444 Rebasing your work onto the NMU
446 % git rebase dgit/dgit/sid
447 If the NMUer added new commits modifying the upstream source, you will
449 probably want to debrebase before your next upload to tidy those up.
450 For example, the NMUer might have used git-revert(1) to unapply one of
452 your patches. A debrebase can be used to strip both the patch and the
453 reversion from the delta queue.
454 Manually applying the debdiff
456 If you cannot rebase because you have already pushed to
457 salsa.debian.org, say, you can manually apply the NMU debdiff, commit
458 and debrebase. The next dgit push will require --overwrite.
459
461 Minimising pseudomerges
462 Above we noted that each time you conclude a debrebase, you introduce a
463 pseudomerge into your git history, which may make it harder to read.
464 A simple convention you can use to minimise the number of pseudomerges
466 is to git debrebase conclude only right before you upload or push to
467 salsa.debian.org.
468 It is possible, though much less convenient, to reduce the number of
470 pseudomerges yet further. We debrebase only (i) when importing a new
471 release, and (ii) right before uploading. Instead of editing the
472 existing delta queue, you append fixup commits (and reversions of
473 commits) that alter the upstream source to the required state. You can
474 push and pull to and from salsa.debian.org during this. Just before
475 uploading, you debrebase, once, to tidy everything up.
476 The debian/patches directory
478 In this workflow, debian/patches is purely an output of
479 git-debrebase(1). You should not make changes there. They will either
480 cause trouble, or be ignored and overwritten by git-debrebase(1).
481 debian/patches will often be out-of-date because git-debrebase(1) will
483 only regenerate it when it needs to. So you should not rely on the
484 information in that directory. When preparing patches to forward
485 upstream, you should use git-format-patch(1) on git commits, rather
486 than sending files from debian/patches.
487 Upstream branches
489 In this workflow, we specify upstream tags rather than any branches.
490 Except when (i) upstream releases only tarballs, (ii) we require DFSG
492 filtering, or (iii) you also happen to be involved in upstream
493 development, we do not maintain any local branch corresponding to
494 upstream, except temporary branches used to prepare patches for
495 forwarding, and the like.
496 The idea here is that from Debian's point of view, upstream releases
498 are immutable points in history. We want to make sure that we are
499 basing our Debian package on a properly identified upstream version,
500 rather than some arbitrary commit on some branch. Tags are more useful
501 for this.
502 Upstream's branches remain available as the git remote tracking
504 branches for your upstream remote, e.g. remotes/upstream/master.
505 The first ever dgit push
507 If this is the first ever dgit push of the package, consider passing
508 --deliberately-not-fast-forward instead of --overwrite. This avoids
509 introducing a new origin commit into your git history. (This origin
510 commit would represent the most recent non-dgit upload of the package,
511 but this should already be represented in your git history.)
512 Inspecting the history
514 The git history made by git-debrebase can seem complicated. Here are
515 some suggestions for helpful invocations of gitk and git. They can be
516 adapted for other tools like tig(1), git-log(1), magit, etc.
517 History of package in Debian, disregarding history from upstream:
519 % gitk --first-parent
521 In a laundered branch, the delta queue is at the top.
523 History of the packaging, excluding the delta queue:
525 % gitk :/debian :!/debian/patches
527 Just the delta queue (i.e. Debian's changes to upstream):
529 % gitk --first-parent -- :/ :!/debian
531 Full history including old versions of the delta queue:
533 % gitk --date-order
535 The "Declare fast forward" commits you see have an older history
537 (usually, an older delta queue) as one parent, and a newer history
538 as the other. --date-order makes gitk show the delta queues in the
539 right order.
540 Complete diff since the last upload:
542 % git diff dgit/dgit/sid..HEAD -- :/ :!/debian/patches
544 This includes changes to upstream files.
546 Interdiff of delta queue since last upload, if you really want it:
548 % git debrebase make-patches
550 % git diff dgit/dgit/sid..HEAD -- debian/patches
551 And of course there is:
553 % git debrebase status
555 Alternative ways to start a debrebase
557 Above we started an interactive debrebase by invoking git-debrebase(1)
558 like this:
559 % git debrebase -i
561 It is also possible to perform a non-interactive rebase, like this:
563 % git debrebase -- [git-rebase options...]
565 A third alternative is to have git-debrebase(1) shuffle all the Debian
567 changes to the end of your branch, and then manipulate them yourself
568 using git-rebase(1) directly. For example,
569 % git debrebase
571 % git rebase -i HEAD~5 # there are 4 Debian patches
572 If you take this approach, you should be very careful not to start the
574 rebase too early, including before the most recent pseudomerge. git-
575 rebase without a base argument will often start the rebase too early,
576 and should be avoided. Run git-debrebase instead. See also "ILLEGAL
577 OPERATIONS" in git-debrebase(5).
578
580 dgit(1), dgit(7), git-debrebase(1), git-debrebase(5)
581
583 This tutorial was written and is maintained by Sean Whitton
584 <spwhitton@spwhitton.name>. It contains contributions from other dgit
585 contributors too - see the dgit copyright file.
586perl v5.36.0 Debian Project dgit-maint-debrebase(7)