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 When upstream releases only tarballs
126 Because we want to work in git, we need a virtual upstream branch with
127 virtual release tags. gbp-import-orig(1) can manage this for us. To
128 begin
129 % mkdir foo
131 % cd foo
132 % git init
133 Now create debian/gbp.conf:
135 [DEFAULT]
137 upstream-branch = upstream
138 debian-branch = master
139 upstream-tag = %(version)s
140 sign-tags = True
142 pristine-tar = False
143 pristine-tar-commit = False
144 [import-orig]
146 merge-mode = merge
147 gbp-import-orig(1) requires a pre-existing upstream branch:
149 % git add debian/gbp.conf && git commit -m "create gbp.conf"
151 % git checkout --orphan upstream
152 % git rm -rf .
153 % git commit --allow-empty -m "initial, empty branch for upstream source"
154 % git checkout -f master
155 Then we can import the upstream version:
157 % gbp import-orig --merge-mode=replace ../foo_1.2.2.orig.tar.xz
159 Our upstream branch cannot be pushed to dgit-repos, but since we will
161 need it whenever we import a new upstream version, we must push it
162 somewhere. The usual choice is salsa.debian.org:
163 % git remote add -f origin salsa.debian.org:Debian/foo.git
165 % git push --follow-tags -u origin master upstream
166 You are now ready to proceed as above, making commits to the debian/
168 directory and to the upstream source. As above, for technical reasons,
169 it is essential that your first commit introduces the debian/ directory
170 containing at least one file, and does nothing else. In other words,
171 make a commit introducing debian/ before patching the upstream source.
172
174 This section explains how to convert an existing Debian package to this
175 workflow. It should be skipped when debianising a new package.
176 If you have an existing git history that you have pushed to an ordinary
178 git server like salsa.debian.org, we start with that. If you don't
179 already have it locally, you'll need to clone it, and obtain the
180 corresponding orig.tar from the archive:
181 % git clone salsa.debian.org:Debian/foo
183 % cd foo
184 % dgit setup-new-tree
185 % origtargz
186 If you don't have any existing git history, or you have history only on
188 the special dgit-repos server, we start with dgit clone:
189 % dgit clone foo
191 % cd foo
192 Then we make new upstream tags available:
194 % git remote add -f upstream https://some.upstream/foo.git
196 We now use a git debrebase convert-from-* command to convert your
198 existing history to the git-debrebase(5) data model. Which command you
199 should use depends on some facts about your repository:
200 (A) There is no delta queue.
202 If there do not exist any Debian patches, use
203 % git debrebase convert-from-gbp
205 (B) There is a delta queue, and patches are unapplied.
207 This is the standard git-buildpackage(1) workflow: there are Debian
208 patches, but the upstream source is committed to git without those
209 patches applied. Use
210 % git debrebase convert-from-gbp
212 If you were not previously using dgit to upload your package (i.e.
214 you were not using the workflow described in dgit-maint-gbp(7)),
215 and you happen to have run dgit fetch sid in this clone of the
216 repository, you will need to pass --fdiverged to this command.
217 (C) There is a delta queue, and patches are applied.
219 Use
220 % git debrebase convert-from-dgit-view
222 Finally, you need to ensure that your git HEAD is dgit-compatible,
224 i.e., it is exactly what you would get if you deleted .git, invoked
225 dpkg-buildpackage -S, and then unpacked the resultant source package.
226 To achieve this, you might need to delete debian/source/local-options.
228 One way to have dgit check your progress is to run dgit build-source.
229
231 git-debrebase(1) does not yet support using git merge to merge
232 divergent branches of development (see "OTHER MERGES" in
233 git-debrebase(5)). You should configure git such that git pull does
234 not try to merge:
235 % git config --local pull.rebase true
237 Now when you pull work from other Debian contributors, git will rebase
239 your work on top of theirs.
240 If you use this clone for upstream development in addition to Debian
242 packaging work, you may not want to set this global setting. Instead,
243 see the branch.autoSetupRebase and branch.<name>.rebase settings in
244 git-config(5).
245
247 There are two steps: obtaining git refs that correspond to the new
248 release, and importing that release using git-debrebase(1).
249 Obtaining the release
251 When upstream tags releases in git
252 % git remote update
254 If you want to package an untagged upstream commit (because upstream
256 does not tag releases or because you want to package an upstream
257 development snapshot), see "Using untagged upstream commits" above.
258 When upstream releases only tarballs
260 You will need the debian/gbp.conf from "When upstream releases only
262 tarballs", above. You will also need your upstream branch. Above, we
263 pushed this to salsa.debian.org. You will need to clone or fetch from
264 there, instead of relying on dgit clone/dgit fetch alone.
265 Then, either
267 % gbp import-orig --no-merge ../foo_1.2.3.orig.tar.xz
269 or if you have a working watch file
271 % gbp import-orig --no-merge --uscan
273 Importing the release
275 % git debrebase new-upstream 1.2.3
276 This invocation of git-debrebase(1) involves a git rebase. You may
278 need to resolve conflicts if the Debian delta queue does not apply
279 cleanly to the new upstream source.
280 If all went well, you can now review the merge of the new upstream
282 release:
283 git diff debian/1.2.2-1..HEAD -- . ':!debian'
285 Also, diff with --name-status and --diff-filter=ADR to see just the
287 list of added or removed files, which is useful to determine whether
288 there are any new or deleted files that may need accounting for in your
289 copyright file.
290 If you obtained a tarball from upstream, you are ready to try a build.
292 If you merged a git tag from upstream, you will first need to generate
293 a tarball:
294 % git deborig
296
298 Just make commits on master that change the contents of debian/.
299
301 Adding new patches
302 Adding new patches is straightforward: just make commits touching only
303 files outside of the debian/ directory. You can also use tools like
304 git-revert(1), git-am(1) and git-cherry-pick(1).
305 Editing patches: starting a debrebase
307 git-debrebase(1) is a wrapper around git-rebase(1) which allows us to
308 edit, re-order and delete patches. Run
309 % git debrebase -i
311 to start an interactive rebase. You can edit, re-order and delete
313 commits just as you would during git rebase -i.
314 Editing patches: finishing a debrebase
316 After completing the git rebase, your branch will not be a fast-forward
317 of the git HEAD you had before the rebase. This means that we cannot
318 push the branch anywhere. If you are ready to upload, dgit push or
319 dgit push-source will take care of fixing this up for you.
320 If you are not yet ready to upload, and want to push your branch to a
322 git remote such as salsa.debian.org,
323 % git debrebase conclude
325 Note that each time you conclude a debrebase you introduce a
327 pseudomerge into your git history, which may make it harder to read.
328 Try to do all of the editing of the delta queue that you think will be
329 needed for this editing session in a single debrebase, so that there is
330 a single debrebase stitch.
331
333 You can use dpkg-buildpackage(1) for test builds. When you are ready
334 to build for an upload, use dgit sbuild, dgit pbuilder or dgit
335 cowbuilder.
336 Upload with dgit push or dgit push-source. Remember to pass --new if
338 the package is new in the target suite.
339 In some cases where you used git debrebase convert-from-gbp since the
341 last upload, it is not possible for dgit to make your history fast-
342 forwarding from the history on dgit-repos. In such cases you will have
343 to pass --overwrite to dgit. git-debrebase will normally tell you if
344 this will be needed.
345 Right before uploading, if you did not just already do so, you might
347 want to have git-debrebase(1) shuffle your branch such that the Debian
348 delta queue appears right at the tip of the branch you will push:
349 % git debrebase
351 % dgit push-source
352 Note that this will introduce a new pseudomerge.
354 After dgit pushing, be sure to git push to salsa.debian.org, if you're
356 using that.
357
359 Illegal material
360 Here we explain how to handle material that is merely DFSG-non-free.
361 Material which is legally dangerous (for example, files which are
362 actually illegal) cannot be handled this way.
363 If you encounter possibly-legally-dangerous material in the upstream
365 source code you should seek advice. It is often best not to make a
366 fuss on a public mailing list (at least, not at first). Instead, email
367 your archive administrators. For Debian that is
368 To: dgit-owner@debian.org, ftpmaster@ftp-master.debian.org
369 DFSG-non-free: When upstream tags releases in git
371 Our approach is to maintain a DFSG-clean upstream branch, and create
372 tags on this branch for each release that we want to import. We then
373 import those tags per "Importing the release", above. In the case of a
374 new package, we base our initial Debianisation on our first DFSG-clean
375 tag.
376 For the first upstream release that requires DFSG filtering:
378 % git checkout -b upstream-dfsg 1.2.3
380 % git rm evil.bin
381 % git commit -m "upstream version 1.2.3 DFSG-cleaned"
382 % git tag -s 1.2.3+dfsg
383 % git checkout master
384 Now either proceed with "Importing the release" on the 1.2.3+dfsg tag,
386 or in the case of a new package,
387 % git branch --unset-upstream
389 % git reset --hard 1.2.3+dfsg
390 and proceed with "INITIAL DEBIANISATION".
392 For subsequent releases (whether or not they require additional
394 filtering):
395 % git checkout upstream-dfsg
397 % git merge 1.2.4
398 % git rm further-evil.bin # if needed
399 % git commit -m "upstream version 1.2.4 DFSG-cleaned" # if needed
400 % git tag -s 1.2.4+dfsg
401 % git checkout master
402 % # proceed with "Importing the release" on 1.2.4+dfsg tag
403 Our upstream-dfsg branch cannot be pushed to dgit-repos, but since we
405 will need it whenever we import a new upstream version, we must push it
406 somewhere. Assuming that you have already set up an origin remote per
407 the above,
408 % git push --follow-tags -u origin master upstream-dfsg
410 DFSG-non-free: When upstream releases only tarballs
412 The easiest way to handle this is to add a Files-Excluded field to
413 debian/copyright, and a uversionmangle setting in debian/watch. See
414 uscan(1). Alternatively, see the --filter option detailed in
415 gbp-import-orig(1).
416
418 In the simplest case,
419 % dgit fetch
421 % git merge --ff-only dgit/dgit/sid
422 If that fails, because your branch and the NMUers' work represent
424 divergent branches of development, you have a number of options. Here
425 we describe the two simplest.
426 Note that you should not try to resolve the divergent branches by
428 editing files in debian/patches. Changes there would either cause
429 trouble, or be overwritten by git-debrebase(1).
430 Rebasing your work onto the NMU
432 % git rebase dgit/dgit/sid
433 If the NMUer added new commits modifying the upstream source, you will
435 probably want to debrebase before your next upload to tidy those up.
436 For example, the NMUer might have used git-revert(1) to unapply one of
438 your patches. A debrebase can be used to strip both the patch and the
439 reversion from the delta queue.
440 Manually applying the debdiff
442 If you cannot rebase because you have already pushed to
443 salsa.debian.org, say, you can manually apply the NMU debdiff, commit
444 and debrebase. The next dgit push will require --overwrite.
445
447 Minimising pseudomerges
448 Above we noted that each time you conclude a debrebase, you introduce a
449 pseudomerge into your git history, which may make it harder to read.
450 A simple convention you can use to minimise the number of pseudomerges
452 is to git debrebase conclude only right before you upload or push to
453 salsa.debian.org.
454 It is possible, though much less convenient, to reduce the number of
456 pseudomerges yet further. We debrebase only (i) when importing a new
457 release, and (ii) right before uploading. Instead of editing the
458 existing delta queue, you append fixup commits (and reversions of
459 commits) that alter the upstream source to the required state. You can
460 push and pull to and from salsa.debian.org during this. Just before
461 uploading, you debrebase, once, to tidy everything up.
462 The debian/patches directory
464 In this workflow, debian/patches is purely an output of
465 git-debrebase(1). You should not make changes there. They will either
466 cause trouble, or be ignored and overwritten by git-debrebase(1).
467 debian/patches will often be out-of-date because git-debrebase(1) will
469 only regenerate it when it needs to. So you should not rely on the
470 information in that directory. When preparing patches to forward
471 upstream, you should use git-format-patch(1) on git commits, rather
472 than sending files from debian/patches.
473 Upstream branches
475 In this workflow, we specify upstream tags rather than any branches.
476 Except when (i) upstream releases only tarballs, (ii) we require DFSG
478 filtering, or (iii) you also happen to be involved in upstream
479 development, we do not maintain any local branch corresponding to
480 upstream, except temporary branches used to prepare patches for
481 forwarding, and the like.
482 The idea here is that from Debian's point of view, upstream releases
484 are immutable points in history. We want to make sure that we are
485 basing our Debian package on a properly identified upstream version,
486 rather than some arbitrary commit on some branch. Tags are more useful
487 for this.
488 Upstream's branches remain available as the git remote tracking
490 branches for your upstream remote, e.g. remotes/upstream/master.
491 The first ever dgit push
493 If this is the first ever dgit push of the package, consider passing
494 --deliberately-not-fast-forward instead of --overwrite. This avoids
495 introducing a new origin commit into your git history. (This origin
496 commit would represent the most recent non-dgit upload of the package,
497 but this should already be represented in your git history.)
498 Inspecting the history
500 The git history made by git-debrebase can seem complicated. Here are
501 some suggestions for helpful invocations of gitk and git. They can be
502 adapted for other tools like tig(1), git-log(1), magit, etc.
503 History of package in Debian, disregarding history from upstream:
505 % gitk --first-parent
507 In a laundered branch, the delta queue is at the top.
509 History of the packaging, excluding the delta queue:
511 % gitk :/debian :!/debian/patches
513 Just the delta queue (i.e. Debian's changes to upstream):
515 % gitk --first-parent -- :/ :!/debian
517 Full history including old versions of the delta queue:
519 % gitk --date-order
521 The "Declare fast forward" commits you see have an older history
523 (usually, an older delta queue) as one parent, and a newer history
524 as the other. --date-order makes gitk show the delta queues in the
525 right order.
526 Complete diff since the last upload:
528 % git diff dgit/dgit/sid..HEAD -- :/ :!/debian/patches
530 This includes changes to upstream files.
532 Interdiff of delta queue since last upload, if you really want it:
534 % git debrebase make-patches
536 % git diff dgit/dgit/sid..HEAD -- debian/patches
537 And of course there is:
539 % git debrebase status
541 Alternative ways to start a debrebase
543 Above we started an interactive debrebase by invoking git-debrebase(1)
544 like this:
545 % git debrebase -i
547 It is also possible to perform a non-interactive rebase, like this:
549 % git debrebase -- [git-rebase options...]
551 A third alternative is to have git-debrebase(1) shuffle all the Debian
553 changes to the end of your branch, and then manipulate them yourself
554 using git-rebase(1) directly. For example,
555 % git debrebase
557 % git rebase -i HEAD~5 # there are 4 Debian patches
558 If you take this approach, you should be very careful not to start the
560 rebase too early, including before the most recent pseudomerge. git-
561 rebase without a base argument will often start the rebase too early,
562 and should be avoided. Run git-debrebase instead. See also "ILLEGAL
563 OPERATIONS" in git-debrebase(5).
564
566 dgit(1), dgit(7), git-debrebase(1), git-debrebase(5)
567
569 This tutorial was written and is maintained by Sean Whitton
570 <spwhitton@spwhitton.name>. It contains contributions from other dgit
571 contributors too - see the dgit copyright file.
572perl v5.30.0 Debian Project dgit-maint-debrebase(7)