1dgit-maint-merge(7)                  dgit                  dgit-maint-merge(7)
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4

NAME

6       dgit - tutorial for package maintainers, using a workflow centered
7       around git-merge(1)
8

INTRODUCTION

10       This document describes elements of a workflow for maintaining a non-
11       native Debian package using dgit.  The workflow makes the following
12       opinionated assumptions:
13
14       •   Git histories should be the non-linear histories produced by
15           git-merge(1), preserving all information about divergent
16           development that was later brought together.
17
18       •   Maintaining convenient and powerful git workflows takes priority
19           over the usefulness of the raw Debian source package.  The Debian
20           archive is thought of as an output format.
21
22           For example, we don't spend time curating a series of quilt
23           patches.  However, in straightforward cases, the information such a
24           series would contain is readily available from dgit-repos.
25
26       •   It is more important to have the Debian package's git history be a
27           descendent of upstream's git history than to use exactly the
28           orig.tar that upstream makes available for download.
29
30       This workflow is less suitable for some packages.  When the Debian
31       delta contains multiple pieces which interact, or which you aren't
32       going to be able to upstream soon, it might be preferable to maintain
33       the delta as a rebasing patch series.  For such a workflow see for
34       example dgit-maint-debrebase(7) and dgit-maint-gbp(7).
35

INITIAL DEBIANISATION

37       This section explains how to start using this workflow with a new
38       package.  It should be skipped when converting an existing package to
39       this workflow.
40
41   When upstream tags releases in git
42       Suppose that the latest stable upstream release is 1.2.2, and this has
43       been tagged '1.2.2' by upstream.
44
45           % git clone -oupstream https://some.upstream/foo.git
46           % cd foo
47           % git verify-tag 1.2.2
48           % git reset --hard 1.2.2
49           % git branch --unset-upstream
50
51       The final command detaches your master branch from the upstream remote,
52       so that git doesn't try to push anything there, or merge unreleased
53       upstream commits.  If you want to maintain a copy of your packaging
54       branch on salsa.debian.org in addition to dgit-repos, you can do
55       something like this:
56
57           % git remote add -f origin salsa.debian.org:Debian/foo.git
58           % git push --follow-tags -u origin master
59
60       Now go ahead and Debianise your package.  Just make commits on the
61       master branch, adding things in the debian/ directory.  If you need to
62       patch the upstream source, just make commits that change files outside
63       of the debian/ directory.  It is best to separate commits that touch
64       debian/ from commits that touch upstream source, so that the latter can
65       be cherry-picked by upstream.
66
67       Note that there is no need to maintain a separate 'upstream' branch,
68       unless you also happen to be involved in upstream development.  We work
69       with upstream tags rather than any branches, except when forwarding
70       patches (see FORWARDING PATCHES UPSTREAM, below).
71
72       Finally, you need an orig tarball:
73
74           % git deborig
75
76       See git-deborig(1) if this fails.
77
78       This tarball is ephemeral and easily regenerated, so we don't commit it
79       anywhere (e.g. with tools like pristine-tar(1)).
80
81       Verifying upstream's tarball releases
82
83           It can be a good idea to compare upstream's released tarballs with
84           the release tags, at least for the first upload of the package.  If
85           they are different, you might need to add some additional steps to
86           your debian/rules, such as running autotools.
87
88           A convenient way to perform this check is to import the tarball as
89           described in the following section, using a different value for
90           'upstream-tag', and then use git-diff(1) to compare the imported
91           tarball to the release tag.  If they are the same, you can use
92           upstream's tarball instead of running git-deborig(1).
93
94       Using untagged upstream commits
95
96           Sometimes upstream does not tag their releases, or you want to
97           package an unreleased git snapshot.  In such a case you can create
98           your own upstream release tag, of the form upstream/ver, where ver
99           is the upstream version you plan to put in debian/changelog.  The
100           upstream/ prefix ensures that your tag will not clash with any tags
101           upstream later creates.
102
103           For example, suppose that the latest upstream release is 1.2.2 and
104           you want to package git commit ab34c21 which was made on
105           2013-12-11.  A common convention is to use the upstream version
106           number 1.2.2+git20131211.ab34c21 and so you could use
107
108               % git tag -s upstream/1.2.2+git20131211.ab34c21 ab34c21
109
110           to obtain a release tag, and then proceed as above.
111
112   When upstream releases only tarballs
113       We need a virtual upstream branch with virtual release tags.
114       gbp-import-orig(1) can manage this for us.  To begin
115
116           % mkdir foo
117           % cd foo
118           % git init
119
120       Now create debian/gbp.conf:
121
122           [DEFAULT]
123           upstream-branch = upstream
124           debian-branch = master
125           upstream-tag = upstream/%(version)s
126
127           sign-tags = True
128           pristine-tar = False
129           pristine-tar-commit = False
130
131           [import-orig]
132           merge-mode = merge
133           merge = False
134
135       gbp-import-orig(1) requires a pre-existing upstream branch:
136
137           % git add debian/gbp.conf && git commit -m "create gbp.conf"
138           % git checkout --orphan upstream
139           % git rm -rf .
140           % git commit --allow-empty -m "initial, empty branch for upstream source"
141           % git checkout -f master
142
143       Then we can import the upstream version:
144
145           % gbp import-orig --merge --merge-mode=replace ../foo_1.2.2.orig.tar.xz
146
147       Our upstream branch cannot be pushed to dgit-repos, but since we will
148       need it whenever we import a new upstream version, we must push it
149       somewhere.  The usual choice is salsa.debian.org:
150
151           % git remote add -f origin salsa.debian.org:Debian/foo.git
152           % git push --follow-tags -u origin master upstream
153
154       You are now ready to proceed as above, making commits to both the
155       upstream source and the debian/ directory.
156

CONVERTING AN EXISTING PACKAGE

158       This section explains how to convert an existing Debian package to this
159       workflow.  It should be skipped when debianising a new package.
160
161   No existing git history
162           % dgit clone foo
163           % cd foo
164           % git remote add -f upstream https://some.upstream/foo.git
165
166   Existing git history using another workflow
167       First, if you don't already have the git history locally, clone it, and
168       obtain the corresponding orig.tar from the archive:
169
170           % git clone git.debian.org:collab-maint/foo
171           % cd foo
172           % origtargz
173
174       Now dump any existing patch queue:
175
176           % git rm -rf debian/patches
177           % git commit -m "drop existing quilt patch queue"
178
179       Then make new upstream tags available:
180
181           % git remote add -f upstream https://some.upstream/foo.git
182
183       Now you simply need to ensure that your git HEAD is dgit-compatible,
184       i.e., it is exactly what you would get if you ran dpkg-buildpackage
185       -i'(?:^|/)\.git(?:/|$)' -I.git -S and then unpacked the resultant
186       source package.
187
188       To achieve this, you might need to delete debian/source/local-options.
189       One way to have dgit check your progress is to run dgit build-source.
190
191       The first dgit push will require --overwrite.  If this is the first
192       ever dgit push of the package, consider passing
193       --deliberately-not-fast-forward instead of --overwrite.  This avoids
194       introducing a new origin commit into your git history.  (This origin
195       commit would represent the most recent non-dgit upload of the package,
196       but this should already be represented in your git history.)
197

SOURCE PACKAGE CONFIGURATION

199   debian/source/options
200       We set some source package options such that dgit can transparently
201       handle the "dropping" and "refreshing" of changes to the upstream
202       source:
203
204           single-debian-patch
205           auto-commit
206
207       You don't need to create this file if you are using the version 1.0
208       source package format.
209
210   Sample text for debian/source/patch-header
211       It is a good idea to explain how a user can obtain a breakdown of the
212       changes to the upstream source:
213
214           The Debian packaging of foo is maintained in git, using the merging
215           workflow described in dgit-maint-merge(7).  There isn't a patch
216           queue that can be represented as a quilt series.
217
218           A detailed breakdown of the changes is available from their
219           canonical representation - git commits in the packaging repository.
220           For example, to see the changes made by the Debian maintainer in
221           the first upload of upstream version 1.2.3, you could use:
222
223               % git clone https://git.dgit.debian.org/foo
224               % cd foo
225               % git log --oneline 1.2.3..debian/1.2.3-1 -- . ':!debian'
226
227           (If you have dgit, use `dgit clone foo`, rather than plain `git
228           clone`.)
229
230           A single combined diff, containing all the changes, follows.
231
232       If you are using the version 1.0 source package format, this text
233       should be added to README.source instead.  The version 1.0 source
234       package format ignores debian/source/patch-header.
235
236       If you're using the version 3.0 (quilt) source package format, you
237       could add this text to README.source instead of
238       debian/source/patch-header, but this might distract from more important
239       information present in README.source.
240

BUILDING AND UPLOADING

242       Use dgit build, dgit sbuild, dgit pbuilder, dgit cowbuilder, dgit push-
243       source, and dgit push as detailed in dgit(1).  If any command fails,
244       dgit will provide a carefully-worded error message explaining what you
245       should do.  If it's not clear, file a bug against dgit.  Remember to
246       pass --new for the first upload.
247
248       If you want to upload with git-debpush(1), for the first upload you
249       should pass the --quilt=smash quilt mode option (see git-debpush(1)).
250
251       As another alternative to dgit build and friends, you can use a tool
252       like gitpkg(1).  This works because like dgit, gitpkg(1) enforces that
253       HEAD has exactly the contents of the source package.  gitpkg(1) is
254       highly configurable, and one dgit user reports using it to produce and
255       test multiple source packages, from different branches corresponding to
256       each of the current Debian suites.
257
258       If you want to skip dgit's checks while iterating on a problem with the
259       package build (for example, you don't want to commit your changes to
260       git), you can just run dpkg-buildpackage(1) or debuild(1) instead.
261

NEW UPSTREAM RELEASES

263   Obtaining the release
264       When upstream tags releases in git
265
266           % git fetch --tags upstream
267
268       If you want to package an untagged upstream commit (because upstream
269       does not tag releases or because you want to package an upstream
270       development snapshot), see "Using untagged upstream commits" above.
271
272       When upstream releases only tarballs
273
274       You will need the debian/gbp.conf from "When upstream releases only
275       tarballs", above.  You will also need your upstream branch.  Above, we
276       pushed this to salsa.debian.org.  You will need to clone or fetch from
277       there, instead of relying on dgit clone/dgit fetch alone.
278
279       Then, either
280
281           % gbp import-orig ../foo_1.2.3.orig.tar.xz
282
283       or if you have a working watch file
284
285           % gbp import-orig --uscan
286
287       In the following, replace 1.2.3 with upstream/1.2.3.
288
289   Reviewing & merging the release
290       It's a good idea to preview the merge of the new upstream release.
291       First, just check for any new or deleted files that may need accounting
292       for in your copyright file:
293
294           % git diff --name-status --diff-filter=ADR master..1.2.3 -- . ':!debian'
295
296       You can then review the full merge diff:
297
298           % git merge-tree `git merge-base master 1.2.3` master 1.2.3 | $PAGER
299
300       Once you're satisfied with what will be merged, update your package:
301
302           % git merge 1.2.3
303           % dch -v1.2.3-1 New upstream release.
304           % git add debian/changelog && git commit -m changelog
305
306       If you obtained a tarball from upstream, you are ready to try a build.
307       If you merged a git tag from upstream, you will first need to generate
308       a tarball:
309
310           % git deborig
311

HANDLING DFSG-NON-FREE MATERIAL

313   When upstream tags releases in git
314       We create a DFSG-clean tag to merge to master:
315
316           % git checkout -b pre-dfsg 1.2.3
317           % git rm evil.bin
318           % git commit -m "upstream version 1.2.3 DFSG-cleaned"
319           % git tag -s 1.2.3+dfsg
320           % git checkout master
321           % git branch -D pre-dfsg
322
323       Before merging the new 1.2.3+dfsg tag to master, you should first
324       determine whether it would be legally dangerous for the non-free
325       material to be publicly accessible in the git history on dgit-repos.
326
327       If it would be dangerous, there is a big problem; in this case please
328       consult your archive administrators (for Debian this is the dgit
329       administrator dgit-owner@debian.org and the ftpmasters
330       ftpmaster@ftp-master.debian.org).
331
332   When upstream releases only tarballs
333       The easiest way to handle this is to add a Files-Excluded field to
334       debian/copyright, and a uversionmangle setting in debian/watch.  See
335       uscan(1).  Alternatively, see the --filter option detailed in
336       gbp-import-orig(1).
337

FORWARDING PATCHES UPSTREAM

339       The basic steps are:
340
341       1.  Create a new branch based off upstream's master branch.
342
343       2.  git-cherry-pick(1) commits from your master branch onto your new
344           branch.
345
346       3.  Push the branch somewhere and ask upstream to merge it, or use
347           git-format-patch(1) or git-request-pull(1).
348
349       For example (and it is only an example):
350
351           % # fork foo.git on GitHub
352           % git remote add -f fork git@github.com:spwhitton/foo.git
353           % git checkout -b fix-error upstream/master
354           % git config branch.fix-error.pushRemote fork
355           % git cherry-pick master^2
356           % git push
357           % # submit pull request on GitHub
358
359       Note that when you merge an upstream release containing your forwarded
360       patches, git and dgit will transparently handle "dropping" the patches
361       that have been forwarded, "retaining" the ones that haven't.
362

INCORPORATING NMUS

364           % dgit pull
365
366       Alternatively, you can apply the NMU diff to your repository.  The next
367       push will then require --overwrite.
368

SEE ALSO

370       dgit(1), dgit(7)
371

AUTHOR

373       This tutorial was written and is maintained by Sean Whitton
374       <spwhitton@spwhitton.name>.  It contains contributions from other dgit
375       contributors too - see the dgit copyright file.
376
377
378
379perl v5.34.0                    Debian Project             dgit-maint-merge(7)
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