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 % git checkout -b upstream
134 % gbp import-orig \
135 --upstream-branch=upstream --debian-branch=master \
136 --upstream-tag='upstream/%(version)s' \
137 --sign-tags --no-pristine-tar \
138 ../foo_1.2.2.orig.tar.xz
139 % git branch -f upstream
140 This should leave you on the master branch. Next, our upstream branch
142 cannot be pushed to dgit-repos, but since we will need it whenever we
143 import a new upstream version, we must push it somewhere. The usual
144 choice is salsa.debian.org:
145 % git remote add -f origin salsa.debian.org:Debian/foo.git
147 % git push --follow-tags -u origin master upstream
148 You are now ready to proceed as above, making commits to the debian/
150 directory and to the upstream source. As above, for technical reasons,
151 it is essential that your first commit introduces the debian/ directory
152 containing at least one file, and does nothing else. In other words,
153 make a commit introducing debian/ before patching the upstream source.
154 A convenient way to ensure this requirement is satisfied is to start by
156 creating debian/gbp.conf:
157 [DEFAULT]
159 upstream-branch = upstream
160 debian-branch = master
161 upstream-tag = upstream/%(version)s
162 sign-tags = True
164 pristine-tar = False
165 pristine-tar-commit = False
166 [import-orig]
168 merge = False
169 and commit that:
171 % git add debian/gbp.conf && git commit -m "create gbp.conf"
173 Note that we couldn't create debian/gbp.conf before now for the same
175 technical reasons which require our first commit to introduce debian/
176 without patching the upstream source. That's why we had to pass a lot
177 of options to our first call to gbp-import-orig(1).
178
180 This section explains how to convert an existing Debian package to this
181 workflow. It should be skipped when debianising a new package.
182 If you have an existing git history that you have pushed to an ordinary
184 git server like salsa.debian.org, we start with that. If you don't
185 already have it locally, you'll need to clone it, and obtain the
186 corresponding orig.tar from the archive:
187 % git clone salsa.debian.org:Debian/foo
189 % cd foo
190 % dgit setup-new-tree
191 % origtargz
192 If you don't have any existing git history, or you have history only on
194 the special dgit-repos server, we start with dgit clone:
195 % dgit clone foo
197 % cd foo
198 Then we make new upstream tags available:
200 % git remote add -f upstream https://some.upstream/foo.git
202 We now use a git debrebase convert-from-* command to convert your
204 existing history to the git-debrebase(5) data model. Which command you
205 should use depends on some facts about your repository:
206 (A) There is no delta queue.
208 If there do not exist any Debian patches, use
209 % git debrebase convert-from-gbp
211 (B) There is a delta queue, and patches are unapplied.
213 This is the standard git-buildpackage(1) workflow: there are Debian
214 patches, but the upstream source is committed to git without those
215 patches applied. Use
216 % git debrebase convert-from-gbp
218 If you were not previously using dgit to upload your package (i.e.
220 you were not using the workflow described in dgit-maint-gbp(7)),
221 and you happen to have run dgit fetch sid in this clone of the
222 repository, you will need to pass --fdiverged to this command.
223 (C) There is a delta queue, and patches are applied.
225 Use
226 % git debrebase convert-from-dgit-view
228 Finally, you need to ensure that your git HEAD is dgit-compatible,
230 i.e., it is exactly what you would get if you deleted .git, invoked
231 dpkg-buildpackage -S, and then unpacked the resultant source package.
232 To achieve this, you might need to delete debian/source/local-options.
234 One way to have dgit check your progress is to run dgit build-source.
235
237 git-debrebase(1) does not yet support using git merge to merge
238 divergent branches of development (see "OTHER MERGES" in
239 git-debrebase(5)). You should configure git such that git pull does
240 not try to merge:
241 % git config --local pull.rebase true
243 Now when you pull work from other Debian contributors, git will rebase
245 your work on top of theirs.
246 If you use this clone for upstream development in addition to Debian
248 packaging work, you may not want to set this global setting. Instead,
249 see the branch.autoSetupRebase and branch.<name>.rebase settings in
250 git-config(5).
251
253 There are two steps: obtaining git refs that correspond to the new
254 release, and importing that release using git-debrebase(1).
255 Obtaining the release
257 When upstream tags releases in git
258 % git fetch --tags upstream
260 If you want to package an untagged upstream commit (because upstream
262 does not tag releases or because you want to package an upstream
263 development snapshot), see "Using untagged upstream commits" above.
264 When upstream releases only tarballs
266 You will need the debian/gbp.conf from "When upstream releases only
268 tarballs", above. You will also need your upstream branch. Above, we
269 pushed this to salsa.debian.org. You will need to clone or fetch from
270 there, instead of relying on dgit clone/dgit fetch alone.
271 Then, either
273 % gbp import-orig ../foo_1.2.3.orig.tar.xz
275 or if you have a working watch file
277 % gbp import-orig --uscan
279 Importing the release
281 % git debrebase new-upstream 1.2.3
282 This invocation of git-debrebase(1) involves a git rebase. You may
284 need to resolve conflicts if the Debian delta queue does not apply
285 cleanly to the new upstream source.
286 If all went well, you can now review the merge of the new upstream
288 release:
289 git diff debian/1.2.2-1..HEAD -- . ':!debian'
291 Also, diff with --name-status and --diff-filter=ADR to see just the
293 list of added or removed files, which is useful to determine whether
294 there are any new or deleted files that may need accounting for in your
295 copyright file.
296 If you obtained a tarball from upstream, you are ready to try a build.
298 If you merged a git tag from upstream, you will first need to generate
299 a tarball:
300 % git deborig
302
304 Just make commits on master that change the contents of debian/.
305
307 Adding new patches
308 Adding new patches is straightforward: just make commits touching only
309 files outside of the debian/ directory. You can also use tools like
310 git-revert(1), git-am(1) and git-cherry-pick(1).
311 Editing patches: starting a debrebase
313 git-debrebase(1) is a wrapper around git-rebase(1) which allows us to
314 edit, re-order and delete patches. Run
315 % git debrebase -i
317 to start an interactive rebase. You can edit, re-order and delete
319 commits just as you would during git rebase -i.
320 Editing patches: finishing a debrebase
322 After completing the git rebase, your branch will not be a fast-forward
323 of the git HEAD you had before the rebase. This means that we cannot
324 push the branch anywhere. If you are ready to upload, dgit push or
325 dgit push-source will take care of fixing this up for you.
326 If you are not yet ready to upload, and want to push your branch to a
328 git remote such as salsa.debian.org,
329 % git debrebase conclude
331 Note that each time you conclude a debrebase you introduce a
333 pseudomerge into your git history, which may make it harder to read.
334 Try to do all of the editing of the delta queue that you think will be
335 needed for this editing session in a single debrebase, so that there is
336 a single debrebase stitch.
337
339 You can use dpkg-buildpackage(1) for test builds. When you are ready
340 to build for an upload, use dgit sbuild, dgit pbuilder or dgit
341 cowbuilder.
342 Upload with dgit push or dgit push-source. Remember to pass --new if
344 the package is new in the target suite.
345 In some cases where you used git debrebase convert-from-gbp since the
347 last upload, it is not possible for dgit to make your history fast-
348 forwarding from the history on dgit-repos. In such cases you will have
349 to pass --overwrite to dgit. git-debrebase will normally tell you if
350 this will be needed.
351 If you want to upload with git-debpush(1), for the first upload you
353 should pass the --quilt=linear quilt mode option (see git-debpush(1)).
354 Right before uploading, if you did not just already do so, you might
356 want to have git-debrebase(1) shuffle your branch such that the Debian
357 delta queue appears right at the tip of the branch you will push:
358 % git debrebase
360 % dgit push-source
361 Note that this will introduce a new pseudomerge.
363 After dgit pushing, be sure to git push to salsa.debian.org, if you're
365 using that.
366
368 Illegal material
369 Here we explain how to handle material that is merely DFSG-non-free.
370 Material which is legally dangerous (for example, files which are
371 actually illegal) cannot be handled this way.
372 If you encounter possibly-legally-dangerous material in the upstream
374 source code you should seek advice. It is often best not to make a
375 fuss on a public mailing list (at least, not at first). Instead, email
376 your archive administrators. For Debian that is
377 To: dgit-owner@debian.org, ftpmaster@ftp-master.debian.org
378 DFSG-non-free: When upstream tags releases in git
380 Our approach is to maintain a DFSG-clean upstream branch, and create
381 tags on this branch for each release that we want to import. We then
382 import those tags per "Importing the release", above. In the case of a
383 new package, we base our initial Debianisation on our first DFSG-clean
384 tag.
385 For the first upstream release that requires DFSG filtering:
387 % git checkout -b upstream-dfsg 1.2.3
389 % git rm evil.bin
390 % git commit -m "upstream version 1.2.3 DFSG-cleaned"
391 % git tag -s 1.2.3+dfsg
392 % git checkout master
393 Now either proceed with "Importing the release" on the 1.2.3+dfsg tag,
395 or in the case of a new package,
396 % git branch --unset-upstream
398 % git reset --hard 1.2.3+dfsg
399 and proceed with "INITIAL DEBIANISATION".
401 For subsequent releases (whether or not they require additional
403 filtering):
404 % git checkout upstream-dfsg
406 % git merge 1.2.4
407 % git rm further-evil.bin # if needed
408 % git commit -m "upstream version 1.2.4 DFSG-cleaned" # if needed
409 % git tag -s 1.2.4+dfsg
410 % git checkout master
411 % # proceed with "Importing the release" on 1.2.4+dfsg tag
412 Our upstream-dfsg branch cannot be pushed to dgit-repos, but since we
414 will need it whenever we import a new upstream version, we must push it
415 somewhere. Assuming that you have already set up an origin remote per
416 the above,
417 % git push --follow-tags -u origin master upstream-dfsg
419 DFSG-non-free: When upstream releases only tarballs
421 The easiest way to handle this is to add a Files-Excluded field to
422 debian/copyright, and a uversionmangle setting in debian/watch. See
423 uscan(1). Alternatively, see the --filter option detailed in
424 gbp-import-orig(1).
425
427 In the simplest case,
428 % dgit fetch
430 % git merge --ff-only dgit/dgit/sid
431 If that fails, because your branch and the NMUers' work represent
433 divergent branches of development, you have a number of options. Here
434 we describe the two simplest.
435 Note that you should not try to resolve the divergent branches by
437 editing files in debian/patches. Changes there would either cause
438 trouble, or be overwritten by git-debrebase(1).
439 Rebasing your work onto the NMU
441 % git rebase dgit/dgit/sid
442 If the NMUer added new commits modifying the upstream source, you will
444 probably want to debrebase before your next upload to tidy those up.
445 For example, the NMUer might have used git-revert(1) to unapply one of
447 your patches. A debrebase can be used to strip both the patch and the
448 reversion from the delta queue.
449 Manually applying the debdiff
451 If you cannot rebase because you have already pushed to
452 salsa.debian.org, say, you can manually apply the NMU debdiff, commit
453 and debrebase. The next dgit push will require --overwrite.
454
456 Minimising pseudomerges
457 Above we noted that each time you conclude a debrebase, you introduce a
458 pseudomerge into your git history, which may make it harder to read.
459 A simple convention you can use to minimise the number of pseudomerges
461 is to git debrebase conclude only right before you upload or push to
462 salsa.debian.org.
463 It is possible, though much less convenient, to reduce the number of
465 pseudomerges yet further. We debrebase only (i) when importing a new
466 release, and (ii) right before uploading. Instead of editing the
467 existing delta queue, you append fixup commits (and reversions of
468 commits) that alter the upstream source to the required state. You can
469 push and pull to and from salsa.debian.org during this. Just before
470 uploading, you debrebase, once, to tidy everything up.
471 The debian/patches directory
473 In this workflow, debian/patches is purely an output of
474 git-debrebase(1). You should not make changes there. They will either
475 cause trouble, or be ignored and overwritten by git-debrebase(1).
476 debian/patches will often be out-of-date because git-debrebase(1) will
478 only regenerate it when it needs to. So you should not rely on the
479 information in that directory. When preparing patches to forward
480 upstream, you should use git-format-patch(1) on git commits, rather
481 than sending files from debian/patches.
482 Upstream branches
484 In this workflow, we specify upstream tags rather than any branches.
485 Except when (i) upstream releases only tarballs, (ii) we require DFSG
487 filtering, or (iii) you also happen to be involved in upstream
488 development, we do not maintain any local branch corresponding to
489 upstream, except temporary branches used to prepare patches for
490 forwarding, and the like.
491 The idea here is that from Debian's point of view, upstream releases
493 are immutable points in history. We want to make sure that we are
494 basing our Debian package on a properly identified upstream version,
495 rather than some arbitrary commit on some branch. Tags are more useful
496 for this.
497 Upstream's branches remain available as the git remote tracking
499 branches for your upstream remote, e.g. remotes/upstream/master.
500 The first ever dgit push
502 If this is the first ever dgit push of the package, consider passing
503 --deliberately-not-fast-forward instead of --overwrite. This avoids
504 introducing a new origin commit into your git history. (This origin
505 commit would represent the most recent non-dgit upload of the package,
506 but this should already be represented in your git history.)
507 Inspecting the history
509 The git history made by git-debrebase can seem complicated. Here are
510 some suggestions for helpful invocations of gitk and git. They can be
511 adapted for other tools like tig(1), git-log(1), magit, etc.
512 History of package in Debian, disregarding history from upstream:
514 % gitk --first-parent
516 In a laundered branch, the delta queue is at the top.
518 History of the packaging, excluding the delta queue:
520 % gitk :/debian :!/debian/patches
522 Just the delta queue (i.e. Debian's changes to upstream):
524 % gitk --first-parent -- :/ :!/debian
526 Full history including old versions of the delta queue:
528 % gitk --date-order
530 The "Declare fast forward" commits you see have an older history
532 (usually, an older delta queue) as one parent, and a newer history
533 as the other. --date-order makes gitk show the delta queues in the
534 right order.
535 Complete diff since the last upload:
537 % git diff dgit/dgit/sid..HEAD -- :/ :!/debian/patches
539 This includes changes to upstream files.
541 Interdiff of delta queue since last upload, if you really want it:
543 % git debrebase make-patches
545 % git diff dgit/dgit/sid..HEAD -- debian/patches
546 And of course there is:
548 % git debrebase status
550 Alternative ways to start a debrebase
552 Above we started an interactive debrebase by invoking git-debrebase(1)
553 like this:
554 % git debrebase -i
556 It is also possible to perform a non-interactive rebase, like this:
558 % git debrebase -- [git-rebase options...]
560 A third alternative is to have git-debrebase(1) shuffle all the Debian
562 changes to the end of your branch, and then manipulate them yourself
563 using git-rebase(1) directly. For example,
564 % git debrebase
566 % git rebase -i HEAD~5 # there are 4 Debian patches
567 If you take this approach, you should be very careful not to start the
569 rebase too early, including before the most recent pseudomerge. git-
570 rebase without a base argument will often start the rebase too early,
571 and should be avoided. Run git-debrebase instead. See also "ILLEGAL
572 OPERATIONS" in git-debrebase(5).
573
575 dgit(1), dgit(7), git-debrebase(1), git-debrebase(5)
576
578 This tutorial was written and is maintained by Sean Whitton
579 <spwhitton@spwhitton.name>. It contains contributions from other dgit
580 contributors too - see the dgit copyright file.
581perl v5.34.1 Debian Project dgit-maint-debrebase(7)