1 @c -*- coding: utf-8; mode: texinfo; -*-
4 @node Working with source code
5 @chapter Working with source code
7 @warning{New contributors should read @ref{Quick start}, and in
8 particular @ref{lily-git}, instead of this chapter.}
10 Advanced contributors will find this material quite useful,
11 particularly if they are working on major new features.
14 * Manually installing lily-git.tcl::
16 * Basic Git procedures::
17 * Advanced Git procedures::
19 * Repository directory structure::
20 * Other Git documentation::
24 @node Manually installing lily-git.tcl
25 @section Manually installing lily-git.tcl
27 We have created an easy-to-use GUI to simplify git for new
28 contributors. If you are comfortable with the command-line, then
29 skip ahead to @ref{Starting with Git}.
31 @warning{These instructions are only for people who are @emph{not}
34 @c there's some duplication in this section with stuff covered in
35 @c Quick Start, but moving it into a macro inside included/ would
36 @c be getting a bit icky. -gp
40 If you haven't already, download and install Git.
44 @item Windows users: download the @code{.exe} file labeled
45 @qq{Full installer for official Git} from:
48 @uref{http://code.google.com/p/msysgit/downloads/list}
51 @item Other operating systems: either install @command{git} with
52 your package manager, or download it from the @qq{Binaries}
56 @uref{http://git-scm.com/download}
63 Download the @command{lily-git.tcl} script from:
65 @c don't change the cgit link below to gitweb; gitweb uses
66 @c long filenames like "scripts_auxiliar_lily-git.tcl"
69 @uref{http://git.sv.gnu.org/cgit/lilypond.git/plain/scripts/auxiliar/lily-git.tcl}
73 To run the program from the command line, navigate to the
74 directory containing @command{lily-git.tcl} and enter:
81 Click on the @qq{Get source} button.
83 This will create a directory called @file{lilypond-git/} within
84 your home directory, and will download the source code into that
85 directory (around 150@tie{}Mb). When the process is finished, the
86 @qq{Command output} window will display @qq{Done}, and the button
87 label will change to say @qq{Update source}.
90 Navigate to the @file{lilypond-git/} directory to view the source
95 @warning{Throughout the rest of this manual, most command-line
96 input should be entered from @file{$LILYPOND_GIT}. This is
97 referred to as the @emph{top source directory}.}
99 Further instructions are in @ref{How to use lily-git}.
102 @node Starting with Git
103 @section Starting with Git
105 Using the Git program directly (as opposed to using the
106 @command{lily-git.tcl} GUI) allows you to have much greater control
107 over the contributing process. You should consider using Git if
108 you want to work on complex projects, or if you want to work on
109 multiple projects concurrently.
114 * Git for the impatient::
115 * Other repositories::
116 * Downloading remote branches::
121 @subsection Setting up
123 @warning{These instructions assume that you are using the
124 command-line version of Git 1.5 or higher. Windows users should
125 skip to @ref{Git on Windows}.}
129 * Initializing a repository::
135 @unnumberedsubsubsec Installing Git
137 If you are using a Unix-based machine, the easiest way to download
138 and install Git is through a package manager such as @command{rpm}
139 or @command{apt-get} -- the installation is generally automatic.
140 The only required package is (usually) called @command{git-core},
141 although some of the auxiliary @command{git@var{*}} packages are
142 also useful (such as @command{gitk}).
144 Alternatively, you can visit the Git website
145 (@uref{http://git-scm.com/}) for downloadable binaries and
149 @node Initializing a repository
150 @unnumberedsubsubsec Initializing a repository
152 Once Git is installed, get a copy of the source code:
155 git clone git://git.sv.gnu.org/lilypond.git ~/lilypond-git
158 The above command will put the it in @file{~/lilypond-git}, where
159 @code{~} represents your home directory.
161 @subsubheading Technical details
163 This creates (within the @file{$LILYPOND_GIT} directory) a
164 subdirectory called @file{.git/}, which Git uses to keep track of
165 changes to the repository, among other things. Normally you don't
166 need to access it, but it's good to know it's there.
169 @node Configuring Git
170 @unnumberedsubsubsec Configuring Git
172 @warning{Throughout the rest of this manual, all command-line
173 input should be entered from the top directory of the Git
174 repository being discussed (eg. @file{$LILYPOND_GIT}). This is
175 referred to as the @emph{top source directory}.}
177 Before working with the copy of the main LilyPond repository, you
178 should configure some basic settings with the
179 @command{git@tie{}config} command. Git allows you to set both
180 global and repository-specific options.
182 To configure settings that affect all repositories, use the
183 @option{--global} command line option. For example, the first
184 two options that you should always set are your @var{name} and
185 @var{email}, since Git needs these to keep track of commit
189 git config --global user.name "@var{John Smith}"
190 git config --global user.email @var{john@@example.com}
193 To configure Git to use colored output where possible, use:
196 git config --global color.ui auto
199 The text editor that opens when using @command{git@tie{}commit}
200 can also be changed. If none of your editor-related environment
201 variables are set ($GIT_EDITOR, $VISUAL, or $EDITOR), the default
202 editor is usually @command{vi} or @command{vim}. If you're not
203 familiar with either of these, you should probably change the
204 default to an editor that you know how to use. For example, to
205 change the default editor to @command{nano}, enter:
208 git config --global core.editor @var{nano}
211 Finally, and in some ways most importantly, let's make sure that
212 we know what branch we're on. If you're not using LilyDev, add
213 this to your @file{~/.bashrc}:
216 export PS1="\u@\h \w\$(__git_ps1)$ "
219 You may need to install the additional @code{bash-completion}
220 package, but it is definitely worth it. After installation
221 you must log out, and then log back in again to enable it.
224 @subsubheading Technical details
226 Git stores the information entered with
227 @command{git@tie{}config@tie{}--global} in the file
228 @file{.gitconfig}, located in your home directory. This file can
229 also be modified directly, without using
230 @command{git@tie{}config}. The @file{.gitconfig} file generated
231 by the above commands would look like this:
236 email = john@@example.com
243 Using the @command{git@tie{}config} command @emph{without} the
244 @option{--global} option configures repository-specific settings,
245 which are stored in the file @file{.git/config}. This file is
246 created when a repository is initialized (using
247 @command{git@tie{}init}), and by default contains these lines:
251 repositoryformatversion = 0
254 logallrefupdates = true
257 However, since different repository-specific options are
258 recommended for different development tasks, it is best to avoid
259 setting any now. Specific recommendations will be mentioned later
263 @node Git for the impatient
264 @subsection Git for the impatient
266 @advanced{The intent of this subsection is to get you working on lilypond as
267 soon as possible. If you want to learn about git, go read
268 @ref{Other Git documentation}.
270 Also, these instructions are designed to eliminate the most common
271 problems we have found in using git. If you already know git and
272 have a different way of working, great! Feel free to ignore the
273 advice in this subsection.}
276 Ok, so you've been using @command{lily-git.tcl} for a while, but
277 it's time to take the next step. Since our review process delays
278 patches by 60-120 hours, and you want to be able to work on other
279 stuff while your previous work is getting reviewed, you're going
280 to use @strong{branches}.
282 You can think of a branch as being a separate copy of the source
283 code. But don't worry about it.
285 @subsubheading Start work: make a new branch
287 Let's pretend you want to add a section to the Contributor's Guide
288 about using branches.
290 Start by updating the repository, then making a new branch. Call
291 the branch anything you want as long as the name starts with
292 @code{dev/}. Branch names that don't begin with @code{dev/} are
293 reserved for special things in lilypond.
297 git pull -r origin master
301 @subsubheading Switch to that branch
303 Nothing has happened to the files yet. Let's change into the new
304 branch. You can think of this as @qq{loading a file}, although in
305 this case it's really @qq{loading a directory and subdirectories
312 Your prompt now shows you that you're on the other branch:
315 gperciva@@LilyDev:~/lilypond-git (dev/cg)$
318 To be able to manage multiple lilypond issues at once, you'll need to switch
319 branches. You should have each lilypond issue on a separate branch.
320 Switching branches is easy:
324 git checkout origin/staging
325 git checkout origin/release/unstable
329 Branches that begin with @code{origin/} are part of the remote repository,
330 rather than your local repository, so when you check them out you get a
331 temporary local branch. You should never make changes directly on a
332 branch beginning with @code{origin/}. You get changes into the remote
333 repository by making them in local branches, and then pushing them to
334 @code{origin/staging} as described below.
336 @subsubheading Make your changes
338 Edit files, then commit them.
345 Remember how I said that switching to a branch was like
346 @qq{loading a directory}? Well, you've just @qq{saved a
347 directory}, so that you can @qq{load} it later.
349 @advanced{If you have used @command{cvs} or @command{svn}, you may
350 be very confused: those programs use @qq{commit} to mean
351 @qq{upload my changes to the shared source repository}.
352 Unfortunately, just to be different, @w{@command{git commit}}
353 means @qq{save my changes to the files}.}
355 When you create a new file, you need to add it to git, then commit it:
358 git add input/regression/avoid-crash-on-condition.ly
363 Edit more files. Commit them again. Edit yet more files, commit
364 them again. Go eat dinner. Switch to @code{master} so you can
365 play with the latest changes from other developers. Switch back
366 to your branch and edit some more. Commit those changes.
368 At this stage, don't worry about how many commits you have.
371 @subsubheading Save commits to external files
373 Branches are nerve-wracking until you get used to them. You can
374 save your hard work as individual @file{.patch} files. Be sure to
375 commit your changes first.
379 git format-patch master
382 I personally have between 4 and 20 of those files saved in a
383 special folder at any point in time. Git experts might laugh as
384 that behavior, but I feel a @emph{lot} better knowing that I've
388 @subsubheading Prepare your branch for review
390 After committing, you can update your branch with the latest master:
395 git pull -r origin master
401 Due to the speed of lilypond development, sometimes
402 @code{master} has changed so much that your branch can no
403 longer be applied to it. In that happens, you will have a merge
404 conflict. Stop for a moment to either cry or have a stiff drink,
405 then proceed to @ref{Merge conflicts}.
408 @subsubheading Upload your branch
410 Finally, you're finished your changes. Time to upload for review.
411 Make sure that you're on your branch, then upload:
419 @subsubheading Wait for reviews
421 While you're waiting for a countdown and reviews, go back to
422 master, make a @code{dev/doc-beams} branch, and start adding doc
423 suggestions from issue 12345 from the tracker. Or make a
424 @code{dev/page-breaks} and fix bug in page breaking. Or whatever.
425 Don't worry, your @code{dev/cg} is safe.
428 @subsubheading Combining commits (optional unless you have broken commits)
430 Does the history of your branch look good?
436 If you have a lot of commits on your branch, you might want to
437 combine some of them. Alternately, you may like your commits, but
438 want to edit the commit messages.
444 Follow instructions on the screen.
446 @warning{This step gives you the power to completely lose your
447 work. Make a backup of your commits by saving them to
448 @file{.patch} files before playing with this. If you do lose
449 your work, don't despair. You can get it back by using @code{git reflog}.
450 The use of @code{git reflog} is not covered here.}
452 @warning{If any of the commits on your branch represent partial work that will
453 not pass @var{make && make doc}, you @strong{must} squash these
454 commits into a working commit. Otherwise, your push will break staging
455 and will not be able to be merged to master. In general, you will
456 be safer to have one commit per push.}
459 @subsubheading Push to staging
461 When you've got the coveted @code{Patch-push} status, time to
466 git rebase origin/staging dev/cg~0
470 @warning{Do not skip the @command{gitk} step; a quick 5-second
471 check of the visual history can save a great deal of frustration
472 later on. You should see a set of your commits that are ahead of
473 @code{origin/staging}, with no label for the top commit -- only a
476 @warning{If @code{origin/staging} and @code{origin/master} are the
477 same commit, your branch (@code{dev/cg} in the example) will also
478 be at the top of the @code{gitk} tree. This is normal.}
480 If everything looks good, push it:
483 git push origin HEAD:staging
486 Then change back to your working branch:
492 @warning{It is a best practice to avoid rebasing any of your branches
493 to @code{origin/staging}. If @code{origin/staging} is broken, it
494 will be deleted and rebuilt. If you have rebased one of your branches
495 to @code{origin/staging}, the broken commits can end up in your branch.
496 The commands given above do the rebase on a temporary branch, and avoid
497 changing your working branch.}
500 @subsubheading Delete your branch (safe)
502 After a few hours, if there's nothing wrong with your branch, it
503 should be automatically moved to @code{origin/master}. Update,
504 then try removing your branch:
508 git pull -r origin master
512 The last command will fail if the contents of @code{dev/cg} are
513 not present in @code{origin/master}.
516 @subsubheading Delete your branch (UNSAFE)
518 @c don't give explicit commands here -- this is too dangerous to copy and paste
519 Sometimes everything goes wrong. If you want to remove a branch even though
520 it will cause your work to be lost (that is, if the contents of @code{dev/cg}
521 are @strong{not} present in master), follow the instructions in @qq{Delete
522 your branch (safe)}, but replace the @code{-d} on the final line with
526 @node Other repositories
527 @subsection Other repositories
529 We have a few other code repositories.
533 * Grand Unified Builder (GUB)::
535 * yet more repositories::
539 @unnumberedsubsubsec lilypond-extra
541 There is a separate repository for general administrative scripts,
542 as well as pictures and media files for the website. People
543 interested in working on the website should download this
544 repository, and set their @code{$LILYPOND_WEB_MEDIA_GIT}
545 environment variable to point to that repository.
548 @uref{https://github.com/gperciva/lilypond-extra}
551 To configure an environment variable in bash (the default for most
552 GNU/Linux distributions),
555 export LILYPOND_WEB_MEDIA_GIT=$HOME/dir/of/lilypond-extra/
558 Be aware that @code{lilypond-extra} is the definitive source for some binary
559 files - in particular PDF versions of papers concerning LilyPond. To add
560 further PDFs of this sort, all that is necessary is to add the PDF to
561 @code{lilypond-extra} and then add a reference to it in the documentation. The
562 file will then be copied to the website when @code{make website} is run.
564 However, pictures that are also used in the documentation build are mastered in
565 the main git repository. If any of these is changed, it should be updated in
566 git, and then the updates copied to @code{lilypond-extra}.
568 @node Grand Unified Builder (GUB)
569 @unnumberedsubsubsec Grand Unified Builder (GUB)
571 Another item of interest might be the Grand Unified Builder, our
572 cross-platform building tool. Since it is used by other projects as
573 well, it is not stored in our gub repository. For more info, see
574 @uref{http://lilypond.org/gub}.
576 There are two locations for this repository: the version being used to
577 build lilypond, which is at
580 @uref{http://github.com/gperciva/gub}
583 and the original version by Jan Nieuwenhuizen, kept at
586 @uref{http://github.com/janneke/gub}
591 @unnumberedsubsubsec LilyPad
593 Our binary releases on MacOS X and Windows contain a lightweight
596 To make any modifications the Windows editor, you will need to do the
601 Clone the git repository from @code{https://github.com/gperciva/lilypad}
604 Make changes to the source, and check it compiles. In a Windows environment
605 @code{MinGW} provides both a @code{Git} installation and a @code{gcc}
606 compiler. This can be obtained from @code{http://www.mingw.org/}
609 Update the version which is contained in the @file{rsrc.rc}. Check
613 Commit the changes with an informative commit message.
616 Push the changes to github. You will need to use syntax similiar to this:
619 git push https://UserName@@github.com/gperciva/lilypad.git
622 You will need to have push access to the git repository for this to be
626 Make a tarball of the source code to be used by GUB by pulling the updated
627 repository from GitHub. Ensure that the tarball has the correct Version
631 Copy the tarball to @code{http://lilypond.org/download/gub-sources/lilypad/}.
632 You will need to have SSH access to @code{lilypond.org}. If you do not, contact
633 the Release Manager via the lilypond-devel mailing list.
636 Update GUB to make it use the new tarball by editing
637 @file{gub/specs/lilypad.py} and changing the @code{source =} line to point to
641 Push this updated @file{lilypad.py} version to the GUB repository on GitHub.
644 Test the changes with a new GUB compile.
648 @node yet more repositories
649 @unnumberedsubsubsec yet more repositories
651 There are a few other repositories floating around, which will
652 hopefully be documented in the near future.
655 @node Downloading remote branches
656 @subsection Downloading remote branches
658 @warning{contains obsolete + misleading info}
661 * Organization of remote branches::
662 * LilyPond repository sources::
663 * Downloading individual branches::
664 * Downloading all remote branches::
669 @node Organization of remote branches
670 @unnumberedsubsubsec Organization of remote branches
673 The main LilyPond repository is organized into @emph{branches} to
674 facilitate development. These are often called @emph{remote}
675 branches to distinguish them from @emph{local} branches you might
676 create yourself (see @ref{Using local branches}).
678 The @code{master} branch contains all the source files used to
679 build LilyPond, which includes the program itself (both stable and
680 development releases), the documentation (and its translations),
681 and the website. Generally, the @code{master} branch is expected
682 to compile successfully.
684 The @code{translation} branch is a side branch that
685 allows translators to work without needing to worry about
686 compilation problems. Periodically, the Translation Meister
687 (after verifying that it doesn't break compilation), will
688 @emph{merge} this branch into @code{staging} to incorporate
689 recent translations. Similarly, the @code{master} branch is
690 usually merged into the @code{translation} branch after
691 significant changes to the English documentation. See
692 @ref{Translating the documentation} for details.
695 @node LilyPond repository sources
696 @unnumberedsubsubsec LilyPond repository sources
699 The recommended source for downloading a copy of the main
703 git://git.sv.gnu.org/lilypond.git
706 However, if your internet router filters out connections using the
707 GIT protocol, or if you experience difficulty connecting via GIT,
708 you can try these other sources:
711 ssh://git.sv.gnu.org/srv/git/lilypond.git
712 http://git.sv.gnu.org/r/lilypond.git
715 The SSH protocol can only be used if your system is properly set
716 up to use it. Also, the HTTP protocol is slowest, so it should
717 only be used as a last resort.
720 @node Downloading individual branches
721 @unnumberedsubsubsec Downloading individual branches
723 @warning{obsolete, should be deleted!}
726 Once you have initialized an empty Git repository on your system
727 (see @ref{Initializing a repository}), you can download a remote
728 branch into it. Make sure you know which branch you want to start
731 To download the @code{master} branch, enter the following:
734 git remote add -ft master -m master \
735 origin git://git.sv.gnu.org/lilypond.git/
738 To download the @code{translation} branch, enter:
741 git remote add -ft translation -m \
742 translation origin git://git.sv.gnu.org/lilypond.git/
745 The @command{git@tie{}remote@tie{}add} process could take up to
746 ten minutes, depending on the speed of your connection. The
747 output will be something like this:
751 remote: Counting objects: 235967, done.
752 remote: Compressing objects: 100% (42721/42721), done.
753 remote: Total 235967 (delta 195098), reused 233311 (delta 192772)
754 Receiving objects: 100% (235967/235967), 68.37 MiB | 479 KiB/s, done.
755 Resolving deltas: 100% (195098/195098), done.
756 From git://git.sv.gnu.org/lilypond
757 * [new branch] master -> origin/master
758 From git://git.sv.gnu.org/lilypond
759 * [new tag] flower/1.0.1 -> flower/1.0.1
760 * [new tag] flower/1.0.10 -> flower/1.0.10
762 * [new tag] release/2.9.6 -> release/2.9.6
763 * [new tag] release/2.9.7 -> release/2.9.7
766 When @command{git@tie{}remote@tie{}add} is finished, the remote
767 branch should be downloaded into your repository---though not yet
768 in a form that you can use. In order to browse the source code
769 files, you need to @emph{create} and @emph{checkout} your own
770 local branch. In this case, however, it is easier to have Git
771 create the branch automatically by using the @command{checkout}
772 command on a non-existent branch. Enter the following:
775 git checkout -b @var{branch} origin/@var{branch}
779 where @code{@var{branch}} is the name of your tracking branch,
780 either @code{master} or @code{translation}.
782 Git will issue some warnings; this is normal:
785 warning: You appear to be on a branch yet to be born.
786 warning: Forcing checkout of origin/master.
787 Branch master set up to track remote branch master from origin.
791 By now the source files should be accessible---you should be able
792 to edit any files in the @file{$LILYPOND_GIT} directory using a
793 text editor of your choice. But don't start just yet! Before
794 editing any source files, learn how to keep your changes organized
795 and prevent problems later---read @ref{Basic Git procedures}.
797 @subsubheading Technical Details
799 The @command{git@tie{}remote@tie{}add} command should add some
800 lines to your local repository's @file{.git/config} file:
804 url = git://git.sv.gnu.org/lilypond.git/
805 fetch = +refs/heads/master:refs/remotes/origin/master
809 @node Downloading all remote branches
810 @unnumberedsubsubsec Downloading all remote branches
813 To download all remote branches at once, you can @command{clone}
814 the entire repository:
817 git clone git://git.sv.gnu.org/lilypond.git
822 @unnumberedsubsubsec Other branches
824 Most contributors will never need to touch the other branches. If
825 you wish to do so, you will need more familiarity with Git; please
826 see @ref{Other Git documentation}.
829 @item @code{dev/XYZ}:
830 These branches are for individual developers. They store code
831 which is not yet stable enough to be added to the @code{master}
834 @item @code{stable/XYZ}:
835 The branches are kept for archival reasons.
837 @item @code{archive/XYZ}:
838 The branches are kept for archival reasons.
843 @node Basic Git procedures
844 @section Basic Git procedures
848 * The Git contributor's cycle::
849 * Pulling and rebasing::
850 * Using local branches::
856 @node The Git contributor's cycle
857 @subsection The Git contributor's cycle
860 Here is a simplified view of the contribution process on Git:
864 Update your local repository by @emph{pulling} the most recent
865 updates from the remote repository.
868 Edit source files within your local repository's @emph{working
872 @emph{Commit} the changes you've made to a local @emph{branch}.
875 Generate a @emph{patch} to share your changes with the developers.
879 @node Pulling and rebasing
880 @subsection Pulling and rebasing
883 When developers push new patches to the @code{git.sv.gnu.org}
884 repository, your local repository is @strong{not} automatically
885 updated. It is important to keep your repository up-to-date by
886 periodically @emph{pulling} the most recent @emph{commits} from
887 the remote branch. Developers expect patches to be as current as
888 possible, since outdated patches require extra work before they
891 Occasionally you may need to rework some of your own modifications
892 to match changes made to the remote branch (see @ref{Resolving
893 conflicts}), and it's considerably easier to rework things
894 incrementally. If you don't update your repository along the way,
895 you may have to spend a lot of time resolving branch conflicts and
896 reconfiguring much of the work you've already done.
898 Fortunately, Git is able to resolve certain types of branch
899 conflicts automatically with a process called @emph{rebasing}.
900 When rebasing, Git tries to modify your old commits so they appear
901 as new commits (based on the latest updates). For a more involved
902 explanation, see the @command{git-rebase} man page.
904 To pull without rebasing (recommended for translators), use the
908 git pull # recommended for translators
911 If you're tracking the remote @code{master} branch, you should add
912 the @option{-r} option (short for @option{--rebase}) to keep commits
913 on your local branch current:
916 git pull -r # use with caution when translating
919 If you don't edit translated documentation and don't want to type
920 @option{-r} every time, configure the master branch to rebase by
921 default with this command:
924 git config branch.master.rebase true
927 If pull fails because of a message like
930 error: Your local changes to 'Documentation/learning/tutorial.itely'
931 would be overwritten by merge. Aborting.
938 Documentation/learning/tutorial.itely: needs update
939 refusing to pull with rebase: your working tree is not up-to-date
943 it means that you have modified some files in you working tree
944 without committing changes (see @ref{Commits}); you
945 can use the @command{git@tie{}stash} command to work around this:
948 git stash # save uncommitted changes
949 git pull -r # pull using rebase (translators omit "-r")
950 git stash pop # reapply previously saved changes
953 Note that @command{git@tie{}stash@tie{}pop} will try to apply a
954 patch, and this may create a conflict. If this happens, see
955 @ref{Resolving conflicts}.
957 TODO: I think the next paragraph is confusing. Perhaps prepare
958 the reader for new terms `committish' and `head'? -mp
960 @warning{translators and documentation editors, if you have
961 changed committishes in the head of translated files using commits
962 you have not yet pushed to @code{git.sv.gnu.org}, please do not
963 rebase. If you want to avoid wondering whether you should rebase
964 each time you pull, please always use committishes from master
965 and/or translation branch on @code{git.sv.gnu.org}, which
966 in particular implies that you must push your changes to
967 documentation except committishes updates (possibly after having
968 rebased), then update the committishes and push them.}
970 TODO: when committishes automatic conditional update have been
971 tested and documented, append the following to the warning above:
972 Note that using update-committishes make target generally touches
975 @subsubheading Technical details
977 The @command{git@tie{}config} command mentioned above adds the
978 line @code{rebase = true} to the master branch in your local
979 repository's @file{.git/config} file:
984 merge = refs/heads/master
989 @node Using local branches
990 @subsection Using local branches
994 * Creating and removing branches::
995 * Listing branches and remotes::
996 * Checking out branches::
1001 @node Creating and removing branches
1002 @unnumberedsubsubsec Creating and removing branches
1005 Local branches are useful when you're working on several different
1006 projects concurrently. To create a new branch, enter:
1009 git branch @var{name}
1012 To delete a branch, enter:
1015 git branch -d @var{name}
1018 Git will ask you for confirmation if it sees that data would be
1019 lost by deleting the branch. Use @option{-D} instead of @option{-d}
1020 to bypass this. Note that you cannot delete a branch if it is
1021 currently checked out.
1024 @node Listing branches and remotes
1025 @unnumberedsubsubsec Listing branches and remotes
1027 You can get the exact path or URL of all remote branches by
1034 To list Git branches on your local repositories, run
1037 git branch # list local branches only
1038 git branch -r # list remote branches
1039 git branch -a # list all branches
1043 @node Checking out branches
1044 @unnumberedsubsubsec Checking out branches
1046 To know the currently checked out branch, i.e. the branch whose
1047 source files are present in your working tree, read the first line
1055 The currently checked out branch is also marked with an asterisk
1056 in the output of @command{git branch}.
1058 You can check out another branch @code{@var{other_branch}}, i.e.
1059 check out @code{@var{other_branch}} to the working tree, by
1063 git checkout @var{other_branch}
1066 Note that it is possible to check out another branch while having
1067 uncommitted changes, but it is not recommended unless you know
1068 what you are doing; it is recommended to run @command{git status}
1069 to check this kind of issue before checking out another branch.
1071 @node Merging branches
1072 @unnumberedsubsubsec Merging branches
1074 To merge branch @code{@var{foo}} into branch @code{@var{bar}},
1075 i.e. to @qq{add} all changes made in branch @code{@var{foo}} to
1076 branch @code{@var{bar}}, run
1079 git checkout @var{bar}
1083 If any conflict happens, see @ref{Resolving conflicts}.
1085 There are common usage cases for merging: as a translator, you will
1086 often want the Translations meister to merge @code{master} into
1087 @code{translation}; on the other hand, the Translations meister wants
1088 to merge @code{translation} into @code{staging} whenever he has
1089 checked that @code{translation} builds successfully.
1097 * Understanding commits::
1103 @node Understanding commits
1104 @unnumberedsubsubsec Understanding commits
1106 Technically, a @emph{commit} is a single point in the history of a
1107 branch, but most developers use the term to mean a @emph{commit
1108 object}, which stores information about a particular revision. A
1109 single commit can record changes to multiple source files, and
1110 typically represents one logical set of related changes (such as a
1111 bug-fix). You can list the ten most recent commits in your
1112 current branch with this command:
1115 git log -10 --oneline
1118 If you're using an older version of Git and get an @q{unrecognized
1119 argument} error, use this instead:
1122 git log -10 --pretty=oneline --abbrev-commit
1125 More interactive lists of the commits on the remote @code{master}
1126 branch are available at
1127 @uref{http://git.sv.gnu.org/gitweb/?p=lilypond.git;a=shortlog} and
1128 @uref{http://git.sv.gnu.org/cgit/lilypond.git/log/}.
1131 @node Making commits
1132 @unnumberedsubsubsec Making commits
1135 Once you have modified some source files in your working
1136 directory, you can make a commit with the following procedure:
1140 Make sure you've configured Git properly (see @ref{Configuring
1141 Git}). Check that your changes meet the requirements described in
1142 @ref{Code style} and/or @ref{Documentation policy}. For advanced
1143 edits, you may also want to verify that the changes don't break
1144 the compilation process.
1147 Run the following command:
1154 to make sure you're on the right branch, and to see which files
1155 have been modified, added or removed, etc. You may need to tell
1156 Git about any files you've added by running one of these:
1159 git add @var{file} # add untracked @var{file} individually
1160 git add . # add all untracked files in current directory
1164 After @command{git@tie{}add}, run @command{git@tie{}status} again
1165 to make sure you got everything. You may also need to modify
1169 Preview the changes about to be committed (to make sure everything
1177 The @code{HEAD} argument refers to the most recent commit on the
1178 currently checked-out branch.
1181 Generate the commit with:
1188 The @option{-a} is short for @option{--all} which includes modified
1189 and deleted files, but only those newly created files that have
1190 previously been added.
1195 @node Commit messages
1196 @unnumberedsubsubsec Commit messages
1199 When you run the @command{git@tie{}commit@tie{}-a} command, Git
1200 automatically opens the default text editor so you can enter a
1201 @emph{commit message}. If you find yourself in a foreign editing
1202 environment, you're probably in @command{vi} or @command{vim}. If
1203 you want to switch to an editor you're more familiar with, quit by
1204 typing @code{:q!} and pressing @code{<Enter>}. See
1205 @ref{Configuring Git} for instructions on changing the default
1208 In any case, Git will open a text file for your commit message
1209 that looks like this:
1213 # Please enter the commit message for your changes. Lines starting
1214 # with '#' will be ignored, and an empty message aborts the commit.
1216 # Changes to be committed:
1217 # (use "git reset HEAD <file>..." to unstage)
1219 # modified: working.itexi
1223 Your commit message should begin with a one-line summary
1224 describing the change (no more than 50 characters long), and if
1225 necessary a blank line followed by several lines giving the
1228 @c $ git log -1 --pretty=medium 4d6f1e5
1230 Doc: add Baerenreiter and Henle solo cello suites
1232 Added comparison of solo cello suite engravings to new essay with
1233 high-res images, fixed cropping on Finale example.
1236 Commit messages often start with a short prefix describing the
1237 general location of the changes. If a commit affects the
1238 documentation in English (or in several languages simultaneously)
1239 the commit message should be prefixed with @qq{Doc:@tie{}}. If
1240 the commit affects only one of the translations, the commit
1241 message should be prefixed with @qq{Doc-@var{**}:@tie{}}, where
1242 @var{**} is the two-letter language code. Commits that affect the
1243 website should use @qq{Web:@tie{}} for English, and
1244 @qq{Web-@var{**}:@tie{}} for the other languages. Also, changes
1245 to a single file are often prefixed with the name of the file
1246 involved. Visit the links listed in @ref{Understanding commits}
1256 * Uploading a patch for review::
1260 @node Making patches
1261 @unnumberedsubsubsec Making patches
1263 If you want to share your changes with other contributors and
1264 developers, you need to generate @emph{patches} from your commits.
1265 We prefer it if you follow the instructions in
1266 @ref{Uploading a patch for review}. However, we present an
1267 alternate method here.
1269 You should always run @command{git@tie{}pull@tie{}-r} (translators
1270 should leave off the @option{-r}) before doing this to ensure that
1271 your patches are as current as possible.
1273 Once you have made one or more commits in your local repository,
1274 and pulled the most recent commits from the remote branch, you can
1275 generate patches from your local commits with the command:
1278 git format-patch origin
1281 The @code{origin} argument refers to the remote tracking branch at
1282 @code{git.sv.gnu.org}. This command generates a separate patch
1283 for each commit that's in the current branch but not in the remote
1284 branch. Patches are placed in the current working directory and
1285 will have names that look something like this:
1288 0001-Doc-Fix-typos.patch
1289 0002-Web-Remove-dead-links.patch
1293 Send an email (must be less than 64 KB) to
1294 @email{lilypond-devel@@gnu.org} briefly explaining your work, with
1295 the patch files attached. Translators should send patches to
1296 @email{translations@@lilynet.net}. After your patches are
1297 reviewed, the developers may push one or more of them to the main
1298 repository or discuss them with you.
1301 @node Uploading a patch for review
1302 @unnumberedsubsubsec Uploading a patch for review
1304 Any non-trivial change should be uploaded to our @qq{Rietveld}
1305 code review website:
1308 @uref{http://codereview.appspot.com/}
1311 You can upload a patch for review by using our custom @code{git-cl}
1312 @q{helper-script}. This section assumes you have already installed,
1313 updated, and configured @code{git-cl}. See @ref{git-cl}.
1315 @warning{Unless you are familiar with branches, only work on one
1316 set of changes at once.}
1318 There are two methods, depending on your git setup.
1322 @strong{Master branch}: (easy option)
1324 If you added your patch to @code{master}, then:
1328 git-cl upload origin/master
1331 @c Mention staging here?
1332 If you have git push ability, make sure that you @emph{remove}
1333 your patch (with @command{git rebase} or @command{git reset})
1334 before pushing other stuff.
1336 @c don't make this one an @example; we don't want to make it easy
1337 @c for people to use this accidently
1338 Notifications of patches are automatically added to our issue
1339 tracker to reduce the chance of patches getting lost. To suppress
1340 this (not recommended), add the @code{-n / --no-code-issue}
1344 @strong{Separate branch}: (complicated option)
1346 Ensure your changes are committed in a separate branch, which should
1347 differ from the reference branch to be used (usually
1348 @code{origin/master}) by just the changes to be uploaded. Checkout the
1349 branch with the changes:
1352 git checkout some-branch-with-changes
1355 If the reference branch is to be @code{origin/master}, ensure that the
1356 branch containing the changes is up-to-date with it. Use
1357 @command{git rebase} or @command{git pull -r} to rebase the branch to
1358 the head of @code{origin/master}. For example:
1361 git pull -r origin master
1364 Finally, start the upload by entering:
1367 git-cl upload <reference SHA1 ID>
1371 where <reference SHA1 ID> is the SHA1 ID of the commit to be used
1372 as a reference source for the patch. Generally, this will be the
1373 SHA1 ID of origin/master, and in that case you can just use the command:
1376 git-cl upload origin/master
1381 First you will see a terminal editor where you can edit the
1382 message that will accompany your patch. @command{git-cl} will
1383 respect the @env{EDITOR} environment variable if defined,
1384 otherwise it will use @command{vi} as the default editor.
1386 After prompting for your Google email address and password, the
1387 patch set will be posted to Rietveld, and you will be given a URL
1390 @warning{Some installations of git-cl fail when uploading a patch
1391 with certain filename extensions. If this happens, it can
1392 generally be fixed by editing the list of exceptions at top of
1395 @subsubheading Announcing your patch set
1397 You should then announce the patch by logging into the code review
1398 issue webpage and using @qq{Publish + Mail Comments} to add a
1399 (mostly bogus) comment to your issue. The text of your comment
1400 will be sent to our developer mailing list.
1402 @warning{There is no automatic notification of a new patch; you
1403 must add a comment yourself.}
1405 @subsubheading Revisions
1407 As revisions are made in response to comments, successive patch sets
1408 for the same issue can be uploaded by reissuing the git-cl command
1409 with the modified branch checked out.
1411 Sometimes in response to comments on revisions, the best way to
1412 work may require creation of a new branch in git. In order to
1413 associate the new branch with an existing Rietveld issue,
1414 the following command can be used:
1417 git-cl issue issue-number
1421 where @code{issue-number} is the number of the existing Rietveld
1424 @subsubheading Resetting git-cl
1426 If @command{git-cl} becomes confused, you can @qq{reset} it by
1433 @subsubheading Wait for a countdown
1435 Your patch will be available for reviews for the next few hours or
1436 days. Three times a week, patches with no known problems are
1437 gathered into a @qq{patch countdown} and their status changed to
1438 @code{patch-countdown}. The countdown is a 48-hour waiting period
1439 in which any final reviews or complaints should be made.
1441 During the countdown, your patch may be set to
1442 @code{patch-needs_work}, indicating that you should fix something
1443 (or at least discuss why the patch needs no modification). If no
1444 problems are found, the patch will be set to @code{patch-push}.
1446 Once a patch has @code{patch-push}, it should be sent to your
1447 mentor for uploading. If you have git push ability, look at
1448 @ref{Pushing to staging}.
1451 @node Advanced Git procedures
1452 @section Advanced Git procedures
1455 @warning{This section is not necessary for normal contributors;
1456 these commands are presented for information for people interested
1457 in learning more about git.}
1459 It is possible to work with several branches on the same local Git
1460 repository; this is especially useful for translators who may have
1461 to deal with both @code{translation} and a stable branch,
1462 e.g. @code{stable/2.12}.
1464 Some Git commands are introduced first, then a workflow with
1465 several Git branches of LilyPond source code is presented.
1470 * Advanced Git concepts::
1471 * Resolving conflicts::
1472 * Reverting all local changes::
1473 * Working with remote branches::
1475 * Applying remote patches::
1476 * Sending and receiving patches via email::
1477 * Cleaning up multiple patches::
1479 * Pushing to staging::
1483 @node Merge conflicts
1484 @subsection Merge conflicts
1486 To be filled in later, and/or moved to a different section. I
1487 just wanted to make sure that I had a stub ready somewhere.
1490 @node Advanced Git concepts
1491 @subsection Advanced Git concepts
1494 A bit of Git vocabulary will be explained below. The following is
1495 only introductory; for a better understanding of Git concepts, you
1496 may wish to read @ref{Other Git documentation}.
1498 The @code{git@tie{}pull@tie{}origin} command above is just a
1499 shortcut for this command:
1502 git pull git://git.sv.gnu.org/lilypond.git/ @var{branch}:origin/@var{branch}
1506 where @code{@var{branch}} is typically @code{master} or
1507 @code{translation}; if you do not know or remember, see
1508 @ref{Downloading remote branches} to remember which commands you
1509 issued or which source code you wanted to get.
1511 A @emph{commit} is a set of changes made to the sources; it also
1512 includes the committish of the parent commit, the name and e-mail
1513 of the @emph{author} (the person who wrote the changes), the name
1514 and e-mail of the @emph{committer} (the person who brings these
1515 changes into the Git repository), and a commit message.
1517 A @emph{committish} is the SHA1 checksum of a commit, a number
1518 made of 40 hexadecimal digits, which acts as the internal unique
1519 identifier for this commit. To refer to a particular revision,
1520 don't use vague references like the (approximative) date, simply
1521 copy and paste the committish.
1523 A @emph{branch} is nothing more than a pointer to a particular
1524 commit, which is called the @emph{head} of the branch; when
1525 referring to a branch, one often actually thinks about its head
1526 and the ancestor commits of the head.
1528 Now we will explain the two last commands you used to get the
1529 source code from Git---see @ref{Downloading individual branches}.
1532 git remote add -ft @var{branch} -m @var{branch} \
1533 origin git://git.sv.gnu.org/lilypond.git/
1535 git checkout -b @var{branch} origin/@var{branch}
1538 The @command{git@tie{}remote} has created a branch called
1539 @code{origin/@var{branch}} in your local Git repository. As this
1540 branch is a copy of the remote branch web from git.sv.gnu.org
1541 LilyPond repository, it is called a @emph{remote branch}, and is
1542 meant to track the changes on the branch from git.sv.gnu.org: it
1543 will be updated every time you run
1544 @command{git@tie{}pull@tie{}origin} or
1545 @command{git@tie{}fetch@tie{}origin}.
1547 The @command{git@tie{}checkout} command has created a branch named
1548 @code{@var{branch}}. At the beginning, this branch is identical
1549 to @code{origin/@var{branch}}, but it will differ as soon as you
1550 make changes, e.g. adding newly translated pages or editing some
1551 documentation or code source file. Whenever you pull, you merge
1552 the changes from @code{origin/@var{branch}} and
1553 @code{@var{branch}} since the last pulling. If you do not have
1554 push (i.e. @qq{write}) access on git.sv.gnu.org, your
1555 @code{@var{branch}} will always differ from
1556 @code{origin/@var{branch}}. In this case, remember that other
1557 people working like you with the remote branch @code{@var{branch}}
1558 of git://git.sv.gnu.org/lilypond.git/ (called
1559 @code{origin/@var{branch}} on your local repository) know nothing
1560 about your own @code{@var{branch}}: this means that whenever you
1561 use a committish or make a patch, others expect you to take the
1562 latest commit of @code{origin/@var{branch}} as a reference.
1564 Finally, please remember to read the man page of every Git command
1565 you will find in this manual in case you want to discover
1566 alternate methods or just understand how it works.
1569 @node Resolving conflicts
1570 @subsection Resolving conflicts
1573 Occasionally an update may result in conflicts -- this happens
1574 when you and somebody else have modified the same part of the same
1575 file and git cannot figure out how to merge the two versions
1576 together. When this happens, you must manually merge the two
1579 If you need some documentation to understand and resolve
1580 conflicts, see paragraphs @emph{How conflicts are presented} and
1581 @emph{How to resolve conflicts} in @command{git merge} man page.
1583 If all else fails, you can follow the instructions in
1584 @ref{Reverting all local changes}. Be aware that this eliminates
1585 any changes you have made!
1588 @node Reverting all local changes
1589 @subsection Reverting all local changes
1591 Sometimes git will become hopelessly confused, and you just want
1592 to get back to a known, stable state. This command destroys any
1593 local changes you have made in the currently checked-out branch,
1594 but at least you get back to the current online version:
1597 git reset --hard origin/master
1601 @node Working with remote branches
1602 @subsection Working with remote branches
1605 @subsubheading Fetching new branches from git.sv.gnu.org
1607 To fetch and check out a new branch named @code{@var{branch}} on
1608 git.sv.gnu.org, run from top of the Git repository
1611 git config --add remote.origin.fetch \
1612 +refs/heads/@var{branch}:refs/remotes/origin/@var{branch}
1614 git checkout --track -b @var{branch} origin/@var{branch}
1617 After this, you can pull @code{@var{branch}} from git.sv.gnu.org
1624 Note that this command generally fetches all branches you added
1625 with @command{git@tie{}remote@tie{}add} (when you initialized the
1626 repository) or @command{git@tie{}config@tie{}--add}, i.e. it
1627 updates all remote branches from remote @code{origin}, then it
1628 merges the remote branch tracked by the current branch into the
1629 current branch. For example, if your current branch is
1630 @code{master}, @code{origin/master} will be merged into
1634 @subsubheading Local clones, or having several working trees
1636 If you play with several Git branches, e.g. @code{master},
1637 @code{translation}, @code{stable/2.12}), you may want to
1638 have one source and build tree for each branch; this is possible
1639 with subdirectories of your local Git repository, used as local
1640 cloned subrepositories. To create a local clone for the branch
1641 named @code{@var{branch}}, run
1644 git checkout @var{branch}
1645 git clone -lsn . @var{subdir}
1650 Note that @code{@var{subdir}} must be a directory name which does
1651 not already exist. In @code{@var{subdir}}, you can use all Git
1652 commands to browse revisions history, commit and uncommit changes;
1653 to update the cloned subrepository with changes made on the main
1654 repository, cd into @code{@var{subdir}} and run
1655 @command{git@tie{}pull}; to send changes made on the subrepository
1656 back to the main repository, run @command{git@tie{}push} from
1657 @code{@var{subdir}}. Note that only one branch (the currently
1658 checked out branch) is created in the subrepository by default; it
1659 is possible to have several branches in a subrepository and do
1660 usual operations (checkout, merge, create, delete...) on these
1661 branches, but this possibility is not detailed here.
1663 When you push @code{@var{branch}} from @code{@var{subdir}} to the
1664 main repository, and @code{@var{branch}} is checked out in the
1665 main repository, you must save uncommitted changes (see
1666 @command{git@tie{}stash}) and do
1667 @command{git@tie{}reset@tie{}--hard} in the main repository in
1668 order to apply pushed changes in the working tree of the main
1676 The commands above don't only bring you the latest version of the
1677 sources, but also the full history of revisions (revisions, also
1678 called commits, are changes made to the sources), stored in the
1679 @file{.git} directory. You can browse this history with
1682 git log # only shows the logs (author, committish and commit message)
1683 git log -p # also shows diffs
1684 gitk # shows history graphically
1687 @warning{The @code{gitk} command may require a separate
1688 @code{gitk} package, available in the appropriate distribution's
1692 @node Applying remote patches
1693 @subsection Applying remote patches
1696 TODO: Explain how to determine if a patch was created with
1697 @code{git@tie{}format-patch}.
1699 Well-formed git patches created with @code{git@tie{}format-patch}
1700 should be committed with the following command:
1706 Patches created without @code{git@tie{}format-patch} can be
1707 applied in two steps. The first step is to apply the patch to the
1708 working tree and the index:
1711 git apply --index @var{patch}
1715 The second step is to commit the changes and give credit to the
1716 author of the patch. This can be done with the following command:
1719 git commit --author="@var{John Smith} <@var{john@@example.com}>"
1722 Please note that using the @code{--index} option for patching is quite
1723 important here and @emph{cannot} reliably be replaced by using the
1724 @code{-a} option when committing: that would only commit files from the
1725 working tree that are already registered with git, so every file that
1726 the patch actually @emph{adds}, like a regtest for a fixed bug, would
1727 get lost. For the same reason, you should not use the git-independent
1728 @samp{patch} program for applying patches.
1730 @node Sending and receiving patches via email
1731 @subsection Sending and receiving patches via email
1734 The default @code{x-diff} MIME type associated with patch files
1735 (i.e., files whose name ends in @code{.patch}) means that the
1736 encoding of line endings may be changed from UNIX to DOS format
1737 when they are sent as attachments. Attempting to apply such an
1738 inadvertently altered patch will cause git to fail with a message
1739 about @q{whitespace errors}.
1741 The solution to such problems is surprisingly simple---just change
1742 the default file extension of patches generated by git to end in
1743 @code{.txt}, for example:
1746 git config format.suffix '.patch.txt'
1749 This should cause email programs to apply the correct base64
1750 encoding to attached patches.
1752 If you receive a patch with DOS instead of UNIX line-endings, it
1753 can be converted back using the @code{dos2unix} utility.
1755 Lots of useful information on email complications with patches is
1756 provided on the Wine wiki at
1757 @uref{http://wiki.winehq.org/GitWine}.
1760 @node Cleaning up multiple patches
1761 @subsection Cleaning up multiple patches
1763 If you have been developing on your own branch for a while, you
1764 may have more commmits than is really sensible. To revise your
1765 work and condense commits, use:
1768 git rebase origin/master
1769 git rebase -i origin/master
1772 @warning{Be a bit cautious -- if you completely remove commits
1773 during the interactive session, you will... err... completely
1774 remove those commits.}
1778 @subsection Commit access
1780 Most contributors are not able to commit patches directly to the
1781 main repository---only members of the LilyPond development team
1782 have @emph{commit access}. If you are a contributor and are
1783 interested in joining the development team, contact the Project
1784 Manager through the mailing list
1785 (@email{lilypond-devel@@gnu.org}). Generally, only contributors
1786 who have already provided a number of patches which have been
1787 pushed to the main repository will be considered for membership.
1789 If you have been approved by the Project Manager, use the
1790 following procedure to obtain commit access:
1794 If you don't already have one, set up a Savannah user account at
1795 @uref{https://savannah.gnu.org/account/register.php}. If your web
1796 browser responds with an @qq{untrusted connection} message when
1797 you visit the link, follow the steps for including the CAcert root
1798 certificate in your browser, given at
1799 @uref{http://savannah.gnu.org/tls/tutorial/}.
1801 @warning{Savannah will silently put your username in lower-case --
1802 do not try to use capital letters.}
1806 After registering, if you are not logged in automatically, login
1807 at @uref{https://savannah.gnu.org/account/login.php}---this should
1808 take you to your @qq{my} page
1809 (@uref{https://savannah.gnu.org/my/}).
1813 Click on the @qq{My Groups} link to access the @qq{My Group
1814 Membership} page. From there, find the @qq{Request for Inclusion}
1815 box and search for @qq{LilyPond}. Among the search results, check
1816 the box labeled @qq{GNU LilyPond Music Typesetter} and write a
1817 brief (required) message for the Project Manager (@qq{Hey it's
1818 me!} should be fine).
1820 Note that you will not have commit access until the Project
1821 Manager activates your membership. Once your membership is
1822 activated, LilyPond should appear under the heading @qq{Groups I'm
1823 Contributor of} on your @qq{My Group Membership} page.
1827 Generate an SSH @q{rsa} key pair. Enter the following at the
1834 When prompted for a location to save the key, press <ENTER> to
1835 accept the default location (@file{~/.ssh/id_rsa}).
1837 Next you are asked to enter an optional passphrase. On most
1838 systems, if you use a passphrase, you will likely be prompted for
1839 it every time you use @command{git@tie{}push} or
1840 @command{git@tie{}pull}. You may prefer this since it can protect
1841 you from your own mistakes (like pushing when you mean to pull),
1842 though you may find it tedious to keep re-entering it.
1844 You can change/enable/disable your passphrase at any time with:
1847 ssh-keygen -f ~/.ssh/id_rsa -p
1850 Note that the GNOME desktop has a feature which stores your
1851 passphrase for you for an entire GNOME session. If you use a
1852 passphrase to @qq{protect you from yourself}, you will want to
1853 disable this feature, since you'll only be prompted once. Run the
1854 following command, then logout of GNOME and log back in:
1857 gconftool-2 --set -t bool \
1858 /apps/gnome-keyring/daemon-components/ssh false
1861 After setting up your passphrase, your private key is saved as
1862 @file{~/.ssh/id_rsa} and your public key is saved as
1863 @file{~/.ssh/id_rsa.pub}.
1867 Register your public SSH @q{rsa} key with Savannah. From the
1868 @qq{My Account Configuration} page, click on @qq{Edit SSH Keys},
1869 then paste the contents of your @file{~/.ssh/id_rsa.pub} file into
1870 one of the @qq{Authorized keys} text fields, and click
1873 Savannah should respond with something like:
1876 Success: Key #1 seen Keys registered
1881 Configure Git to use the SSH protocol (instead of the GIT
1882 protocol). From your local Git repository, enter:
1885 git config remote.origin.url \
1886 ssh://@var{user}@@git.sv.gnu.org/srv/git/lilypond.git
1890 replacing @var{user} with your Savannah username.
1894 After your membership has been activated and you've configured Git
1895 to use SSH, test the connection with:
1901 SSH should issue the following warning:
1904 The authenticity of host 'git.sv.gnu.org (140.186.70.72)' can't
1906 RSA key fingerprint is
1907 80:5a:b0:0c:ec:93:66:29:49:7e:04:2b:fd:ba:2c:d5.
1908 Are you sure you want to continue connecting (yes/no)?
1911 Make sure the RSA key fingerprint displayed matches the one above.
1912 If it doesn't, respond @qq{no} and check that you configured Git
1913 properly in the previous step. If it does match, respond
1914 @qq{yes}. SSH should then issue another warning:
1917 Warning: Permanently added 'git.sv.gnu.org,140.186.70.72' (RSA) to
1918 the list of known hosts.
1921 The list of known hosts is stored in the file
1922 @file{~/.ssh/known_hosts}.
1924 At this point, you are prompted for your passphrase if you have
1925 one, then Git will attempt a pull.
1927 If @command{git@tie{}pull@tie{}--verbose} fails, you should see
1928 error messages like these:
1931 Permission denied (publickey).
1932 fatal: The remote end hung up unexpectedly
1935 If you get the above error, you may have made a mistake when
1936 registering your SSH key at Savannah. If the key is properly
1937 registered, you probably just need to wait for the Savannah server
1938 to activate it. It usually takes a few minutes for the key to be
1939 active after registering it, but if it still doesn't work after an
1940 hour, ask for help on the mailing list.
1942 If @command{git@tie{}pull@tie{}--verbose} succeeds, the output
1943 will include a @q{From} line that shows @q{ssh} as the protocol:
1946 From ssh://git.sv.gnu.org/srv/git/lilypond
1949 If the protocol shown is not @q{ssh}, check that you configured
1950 Git properly in the previous step.
1954 Test your commit access with a dry run:
1956 @warning{Do not push directly to master; instead, push to staging.
1957 See @ref{Pushing to staging}.}
1960 git push --dry-run --verbose
1963 Note that recent versions of Git (Git 1.6.3 or later) will issue a
1964 big warning if the above command is used. The simplest solution
1965 is to tell Git to push all matching branches by default:
1968 git config push.default matching
1972 Then @code{git@tie{}push} should work as before. For more
1973 details, consult the @code{git@tie{}push} man page.
1977 Repeat the steps from generating an RSA key through to testing
1978 your commit access, for each machine from which you will be
1979 making commits, or you may simply copy the files from your
1980 local @file{~/.ssh} folder to the same folder on the other
1985 @subsubheading Technical details
1989 On Firefox, to view or remove the CAcert root certificate, go to:
1990 Edit > Preferences > Advanced > Encryption > View Certificates >
1991 Authorities > Certificate Name > Root CA > CA Cert Signing
1995 The @command{git@tie{}config} commands above should modify your
1996 local repository's @file{.git/config} file. These lines:
2000 url = git://git.sv.gnu.org/lilypond.git/
2004 should now be changed to:
2008 url = ssh://@var{user}@@git.sv.gnu.org/srv/git/lilypond.git
2012 where @var{user} is your login name on Savannah.
2016 @command{git@tie{}config@tie{}push.default@tie{}matching} command
2017 should add these lines to @file{.git/config}:
2026 Encryption protocols, including ssh, generally do not permit packet
2027 fragmentation to avoid introducing a point of insecurity. This
2028 means that the maximum packet size must not exceed the smallest
2029 MTU (Maximum Transmission Unit) set in the routers along the path.
2030 This smallest MTU is determined by a procedure during call set-up
2031 which relies on the transmission over the path of ICMP packets.
2032 If any of the routers in the path block ICMP packets this mechanism
2033 fails, resulting in the possibility of packets being transmitted
2034 which exceed the MTU of one of the routers. If this happens the
2035 packet is discarded, causing the ssh session to hang, timeout or
2036 terminate with the error message
2039 ssh: connect to host <host ip addr> port 22: Bad file number
2040 fatal: The remote end hung up unexpectedly
2043 depending on precisely when in the proceedings the first large
2044 packet is transmitted. Most routers on the internet have MTU
2045 set to 1500, but routers installed in homes to connect via
2046 broadband may use a slightly smaller MTU for efficient transmission
2047 over ATM. If this problem is encountered a possible work-around is
2048 to set the MTU in the local router to 1500.
2051 @node Pushing to staging
2052 @subsection Pushing to staging
2054 Do not push directly to the git @code{master} branch. Instead,
2055 push to @code{staging}.
2057 You will not see your patch on @code{origin/master} until some
2058 automatic tests have been run. These tests are run every couple
2059 of hours; please wait at least 12 hours before wondering if your
2060 patch has been lost. Note that you can check the commits on
2061 @code{origin/staging} by looking at the git web interface on
2064 It may happen occasionally that the staging branch breaks automated
2065 testing. In this case the automatic move of staging material to
2066 master gets halted in order to avoid broken material entering master.
2067 This is a safety net. Please do not try breaking out from it by
2068 adding fixes on top of staging: in that case the whole sequence will
2069 end up in master after all, defeating the purpose of the system. The
2070 proper fix usually involves rewriting the staging branch and is best
2071 left to core developers after discussion on the developer list.
2073 @subsubheading If your work is in a patch file
2075 Assuming that your patch is in a file called
2076 @file{0001-my-patch.patch}, and you are currently on git master,
2080 git checkout staging
2082 git am 0001-my-patch.patch
2084 git push origin staging
2088 @warning{Do not skip the @command{gitk} step; a quick 5-second
2089 check of the visual history can save a great deal of frustration
2090 later on. You should only see that @command{staging} is only 1
2091 commit ahead of @code{origin/staging}.}
2093 @subsubheading If your work is in a branch
2095 If you are working on branches and your work in is
2096 @code{my_branch_name}, then do:
2099 git checkout staging
2101 git merge my_branch_name
2103 git push origin staging
2106 @warning{Do not skip the @command{gitk} step; a quick 5-second
2107 check of the visual history can save a great deal of frustration
2108 later on. You should see that @code{staging} is only ahead of
2109 @code{origin/staging} by the commits from your branch.}
2113 @node Git on Windows
2114 @section Git on Windows
2116 @warning{We heavily recommend that development be done with our
2117 virtual machine @ref{LilyDev}.}
2119 @c Some of this may duplicate stuff in other sections
2120 @c But it is probably best for windows users to have it all together
2121 @c If necessary, clear this up later -td
2123 TODO: Decide what to do with this... Pare it down? Move
2124 paragraphs next to analogous Unix instructions? -mp
2126 @subsection Background to nomenclature
2128 Git is a system for tracking the changes made to source files by a
2129 distributed set of editors. It is designed to work without a
2130 master repository, but we have chosen to have a master repository
2131 for LilyPond files. Editors hold a local copy of the master
2132 repository together with any changes they have made locally.
2133 Local changes are held in a local @q{branch}, of which there may
2134 be several, but these instructions assume you are using just one.
2135 The files visible in the local repository always correspond to
2136 those on the currently @q{checked out} local branch.
2138 Files are edited on a local branch, and in that state the changes
2139 are said to be @q{unstaged}. When editing is complete, the
2140 changes are moved to being @q{staged for commit}, and finally the
2141 changes are @q{committed} to the local branch. Once committed,
2142 the changes (called a @q{commit}) are given a unique 40-digit
2143 hexadecimal reference number called the @q{Committish} or @q{SHA1
2144 ID} which identifies the commit to Git. Such committed changes
2145 can be sent to the master repository by @q{pushing} them (if you
2146 have write permission) or by sending them by email to someone who
2147 has, either as a complete file or as a @q{diff} or @q{patch}
2148 (which send just the differences from the master repository).
2150 @subsection Installing git
2153 @uref{http://code.google.com/p/msysgit/downloads/list} (note, not
2154 msysGit, which is for Git developers and not PortableGit, which is
2155 not a full git installation) and install it.
2157 Note that most users will not need to install SSH. That is not
2158 required until you have been granted direct push permissions to
2159 the master git repository.
2161 Start Git by clicking on the desktop icon. This will bring up a
2162 command line bash shell. This may be unfamiliar to Windows users.
2163 If so, follow these instructions carefully. Commands are entered
2164 at a $ prompt and are terminated by keying a newline.
2166 @subsection Initialising Git
2168 Decide where you wish to place your local Git repository, creating
2169 the folders in Windows as necessary. Here we call the folder to
2170 contain the repository @code{[path]/Git}, but if you intend using
2171 Git for other projects a directory name like @code{lilypond-git}
2172 might be better. You will need to have space for around
2175 Start the Git bash shell by clicking on the desk-top icon
2176 installed with Git and type
2182 to position the shell at your new Git repository.
2184 Note: if [path] contains folders with names containing spaces use
2196 to initialize your Git repository.
2198 Then type (all on one line; the shell will wrap automatically)
2201 git remote add -ft master origin git://git.sv.gnu.org/lilypond.git
2204 to download the lilypond master files.
2206 @warning{Be patient! Even on a broadband connection this can take
2207 10 minutes or more. Wait for lots of [new tag] messages and the $
2210 We now need to generate a local copy of the downloaded files in a
2211 new local branch. Your local branch needs to have a name. It is
2212 usual to call it @q{master} and we shall do that here.
2217 git checkout -b master origin/master
2220 This creates a second branch called @q{master}. You will see two
2221 warnings (ignore these), and a message advising you that your
2222 local branch @q{master} has been set up to track the remote
2223 branch. You now have two branches, a local branch called
2224 @q{master}, and a tracking branch called @q{origin/master}, which
2225 is a shortened form of @q{remotes/origin/master}.
2227 Return to Windows Explorer and look in your Git repository. You
2228 should see lots of folders. For example, the LilyPond
2229 documentation can be found in [path]/Git/Documentation/.
2231 The Git bash shell is terminated by typing @code{exit} or by
2232 clicking on the usual Windows close-window widget.
2236 Almost all subsequent work will use the Git Graphical User
2237 Interface, which avoids having to type command line commands. To
2238 start Git GUI first start the Git bash shell by clicking on the
2239 desktop icon, and type
2246 The Git GUI will open in a new window. It contains four panels
2247 and 7 pull-down menus. At this stage do not use any of the
2248 commands under Branch, Commit, Merge or Remote. These will be
2251 The top panel on the left contains the names of files which you
2252 are in the process of editing (Unstaged Changes), and the lower
2253 panel on the left contains the names of files you have finished
2254 editing and have staged ready for committing (Staged Changes). At
2255 present, these panels will be empty as you have not yet made any
2256 changes to any file. After a file has been edited and saved the
2257 top panel on the right will display the differences between the
2258 edited file selected in one of the panels on the left and the last
2259 version committed on the current branch.
2261 The panel at bottom right is used to enter a descriptive message
2262 about the change before committing it.
2264 The Git GUI is terminated by entering CNTL-Q while it is the
2265 active window or by clicking on the usual Windows close-window
2268 @subsection Personalising your local git repository
2270 Open the Git GUI, click on
2276 and enter your name and email address in the left-hand (Git
2277 Repository) panel. Leave everything else unchanged and save it.
2279 Note that Windows users must leave the default setting for line
2280 endings unchanged. All files in a git repository must have lines
2281 terminated by just a LF, as this is required for Merge to work,
2282 but Windows files are terminated by CRLF by default. The git
2283 default setting causes the line endings of files in a Windows git
2284 repository to be flipped automatically between LF and CRLF as
2285 required. This enables files to be edited by any Windows editor
2286 without causing problems in the git repository.
2288 @subsection Checking out a branch
2290 At this stage you have two branches in your local repository,
2291 both identical. To see them click on
2297 You should have one local branch called @q{master} and one
2298 tracking branch called @q{origin/master}. The latter is your
2299 local copy of the @q{remotes/origin/master} branch in the master
2300 LilyPond repository. The local @q{master} branch is where you
2301 will make your local changes.
2303 When a particular branch is selected, i.e., checked out, the files
2304 visible in your repository are changed to reflect the state of the
2305 files on that branch.
2307 @subsection Updating files from @q{remote/origin/master}
2309 Before starting the editing of a file, ensure your local
2310 repository contains the latest version of the files in the remote
2311 repository by first clicking
2314 Remote -> Fetch from -> origin
2320 This will place the latest version of every file, including all
2321 the changes made by others, into the @q{origin/master} branch of
2322 the tracking branches in your git repository. You can see these
2323 files by checking out this branch, but you must @emph{never} edit
2324 any files while this branch is checked out. Check out your local
2325 @q{master} branch again.
2327 You then need to merge these fetched files into your local
2328 @q{master} branch by clicking on
2331 Merge -> Local Merge
2335 and if necessary select the local @q{master} branch.
2337 Note that a merge cannot be completed if you have made any local
2338 changes which have not yet been committed.
2340 This merge will update all the files in the @q{master} branch to
2341 reflect the current state of the @q{origin/master} branch. If any
2342 of the changes conflict with changes you have made yourself
2343 recently you will be notified of the conflict (see below).
2345 @subsection Editing files
2347 First ensure your @q{master} branch is checked out, then simply
2348 edit the files in your local Git repository with your favourite
2349 editor and save them back there. If any file contains non-ASCII
2350 characters ensure you save it in UTF-8 format. Git will detect
2351 any changes whenever you restart Git GUI and the file names will
2352 then be listed in the Unstaged Changes panel. Or you can click
2353 the Rescan button to refresh the panel contents at any time. You
2354 may break off and resume editing any time.
2356 The changes you have made may be displayed in diff form in the top
2357 right-hand panel of Git GUI by clicking on the file name shown in
2358 one of the left panels.
2360 When your editing is complete, move the files from being Unstaged
2361 to Staged by clicking the document symbol to the left of each
2362 name. If you change your mind it can be moved back by clicking on
2363 the ticked box to the left of the name.
2365 Finally the changes you have made may be committed to your
2366 @q{master} branch by entering a brief message in the Commit
2367 Message box and clicking the Commit button.
2369 If you wish to amend your changes after a commit has been made,
2370 the original version and the changes you made in that commit may
2371 be recovered by selecting
2374 Commit -> Amend Last Commit
2378 or by checking the Amend Last Commit radio button at bottom right.
2379 This will return the changes to the Staged state, so further
2380 editing made be carried out within that commit. This must only be
2381 done @emph{before} the changes have been Pushed or sent to your
2382 mentor for Pushing - after that it is too late and corrections
2383 have to be made as a separate commit.
2386 @subsection Sending changes to @q{remotes/origin/master}
2388 If you do not have write access to @q{remotes/origin/master} you
2389 will need to send your changes by email to someone who does.
2391 First you need to create a diff or patch file containing your
2392 changes. To create this, the file must first be committed. Then
2393 terminate the Git GUI. In the git bash shell first cd to your Git
2400 if necessary, then produce the patch with
2403 git format-patch origin
2406 This will create a patch file for all the locally committed files
2407 which differ from @q{origin/master}. The patch file can be found
2408 in [path]/Git and will have a name formed from the commit message.
2410 @subsection Resolving merge conflicts
2412 As soon as you have committed a changed file your local
2413 @code{master} branch has diverged from @code{origin/master}, and
2414 will remain diverged until your changes have been committed in
2415 @code{remotes/origin/master} and Fetched back into your
2416 @code{origin/master} branch. Similarly, if a new commit has been
2417 made to @code{remotes/origin/master} by someone else and Fetched,
2418 your local @code{master} branch is divergent. You can detect a
2419 divergent branch by clicking on
2422 Repository -> Visualise all branch history
2425 This opens up a very useful new window called @q{gitk}. Use this
2426 to browse all the commits made by yourself and others.
2428 If the diagram at top left of the resulting window does not show
2429 your @code{master} tag on the same node as the
2430 @code{remotes/origin/master} tag your branch has diverged from
2431 @code{origin/master}. This is quite normal if files you have
2432 modified yourself have not yet been Pushed to
2433 @code{remotes/origin/master} and Fetched, or if files modified and
2434 committed by others have been Fetched since you last Merged
2435 @code{origin/master} into your local @code{master} branch.
2437 If a file being merged from @code{origin/master} differs from one
2438 you have modified in a way that cannot be resolved automatically
2439 by git, Merge will report a Conflict which you must resolve by
2440 editing the file to create the version you wish to keep.
2442 This could happen if the person updating
2443 @code{remotes/origin/master} for you has added some changes of his
2444 own before committing your changes to
2445 @code{remotes/origin/master}, or if someone else has changed the
2446 same file since you last fetched the file from
2447 @code{remotes/origin/master}.
2449 Open the file in your editor and look for sections which are
2452 [to be completed when I next have a merge conflict to be sure I
2453 give the right instructions -td]
2456 @subsection Other actions
2458 The instructions above describe the simplest way of using git on
2459 Windows. Other git facilities which may usefully supplement these
2463 @item Using multiple local branches (Create, Rename, Delete)
2464 @item Resetting branches
2465 @item Cherry-picking commits
2466 @item Pushing commits to @w{remote/origin/master}
2467 @item Using gitk to review history
2470 Once familiarity with using git on Windows has been gained the
2471 standard git manuals can be used to learn about these.
2474 @node Repository directory structure
2475 @section Repository directory structure
2478 @c TODO: integrate the roadmap better
2479 @verbatiminclude ROADMAP
2482 @node Other Git documentation
2483 @section Other Git documentation
2487 Official git man pages:
2488 @uref{http://www.kernel.org/pub/software/scm/git/docs/}
2491 More in-depth tutorials: @uref{http://git-scm.com/documentation}
2494 Book about git: @uref{http://progit.org/,Pro Git}
2497 Github help: @uref{http://help.github.com/}
2498 (very highly recommended by Graham)