4 Consistent formatting of this file is achieved with:
5 perl ./Porting/podtidy pod/perlrepository.pod
9 perlrepository - Using the Perl source repository
13 All of Perl's source code is kept centrally in a Git repository at
14 I<perl5.git.perl.org>. The repository contains many Perl revisions from
15 Perl 1 onwards and all the revisions from Perforce, the version control
16 system we were using previously. This repository is accessible in
19 The full repository takes up about 80MB of disk space. A check out of
20 the blead branch (that is, the main development branch, which contains
21 bleadperl, the development version of perl 5) takes up about 160MB of
22 disk space (including the repository). A build of bleadperl takes up
23 about 200MB (including the repository and the check out).
25 =head1 Getting access to the repository
27 =head2 Read access via the web
29 You may access the repository over the web. This allows you to browse
30 the tree, see recent commits, subscribe to RSS feeds for the changes,
31 search for particular commits and more. You may access it at:
33 http://perl5.git.perl.org/perl.git
35 A mirror of the repository is found at:
37 http://github.com/mirrors/perl
39 =head2 Read access via Git
41 You will need a copy of Git for your computer. You can fetch a copy of
42 the repository using the Git protocol (which uses port 9418):
44 % git clone git://perl5.git.perl.org/perl.git perl-git
46 This clones the repository and makes a local copy in the F<perl-git>
49 If your local network does not allow you to use port 9418, then you can
50 fetch a copy of the repository over HTTP (this is at least 4x slower):
52 % git clone http://perl5.git.perl.org/perl.git perl-http
54 This clones the repository and makes a local copy in the F<perl-http>
57 =head2 Write access to the repository
59 If you are a committer, then you can fetch a copy of the repository
60 that you can push back on with:
62 % git clone ssh://perl5.git.perl.org/perl.git perl-ssh
64 This clones the repository and makes a local copy in the F<perl-ssh>
67 If you cloned using the git protocol, which is faster than ssh, then
68 you will need to modify the URL for the origin remote to enable
69 pushing. To do that edit F<.git/config> with git-config(1) like
72 % git config remote.origin.url ssh://perl5.git.perl.org/perl.git
74 You can also set up your user name and e-mail address. Most people do
75 this once globally in their F<~/.gitconfig> by doing something like:
77 % git config --global user.name "Ævar Arnfjörð Bjarmason"
78 % git config --global user.email avarab@gmail.com
80 However if you'd like to override that just for perl then execute then
81 execute something like the following in F<perl-git>:
83 % git config user.email avar@cpan.org
85 It is also possible to keep C<origin> as a git remote, and add a new
86 remote for ssh access:
88 % git remote add camel perl5.git.perl.org:/perl.git
90 This allows you to update your local repository by pulling from
91 C<origin>, which is faster and doesn't require you to authenticate, and
92 to push your changes back with the C<camel> remote:
97 The C<fetch> command just updates the C<camel> refs, as the objects
98 themselves should have been fetched when pulling from C<origin>.
100 =head2 A note on camel and dromedary
102 The committers have SSH access to the two servers that serve
103 C<perl5.git.perl.org>. One is C<perl5.git.perl.org> itself (I<camel>),
104 which is the 'master' repository. The second one is
105 C<users.perl5.git.perl.org> (I<dromedary>), which can be used for
106 general testing and development. Dromedary syncs the git tree from
107 camel every few minutes, you should not push there. Both machines also
108 have a full CPAN mirror in /srv/CPAN, please use this. To share files
109 with the general public, dromedary serves your ~/public_html/ as
110 C<http://users.perl5.git.perl.org/~yourlogin/>
112 These hosts have fairly strict firewalls to the outside. Outgoing, only
113 rsync, ssh and git are allowed. For http and ftp, you can use
114 http://webproxy:3128 as proxy. Incoming, the firewall tries to detect
115 attacks and blocks IP addresses with suspicious activity. This
116 sometimes (but very rarely) has false positives and you might get
117 blocked. The quickest way to get unblocked is to notify the admins.
119 These two boxes are owned, hosted, and operated by booking.com. You can
120 reach the sysadmins in #p5p on irc.perl.org or via mail to
121 C<perl5-porters@perl.org>
123 =head1 Overview of the repository
125 Once you have changed into the repository directory, you can inspect
128 After a clone the repository will contain a single local branch, which
129 will be the current branch as well, as indicated by the asterisk.
134 Using the -a switch to C<branch> will also show the remote tracking
135 branches in the repository:
143 The branches that begin with "origin" correspond to the "git remote"
144 that you cloned from (which is named "origin"). Each branch on the
145 remote will be exactly tracked by theses branches. You should NEVER do
146 work on these remote tracking branches. You only ever do work in a
147 local branch. Local branches can be configured to automerge (on pull)
148 from a designated remote tracking branch. This is the case with the
149 default branch C<blead> which will be configured to merge from the
150 remote tracking branch C<origin/blead>.
152 You can see recent commits:
156 And pull new changes from the repository, and update your local
157 repository (must be clean first)
161 Assuming we are on the branch C<blead> immediately after a pull, this
162 command would be more or less equivalent to:
165 % git merge origin/blead
167 In fact if you want to update your local repository without touching
168 your working directory you do:
172 And if you want to update your remote-tracking branches for all defined
173 remotes simultaneously you can do
177 Neither of these last two commands will update your working directory,
178 however both will update the remote-tracking branches in your
181 To make a local branch of a remote branch:
183 % git checkout -b maint-5.10 origin/maint-5.10
185 To switch back to blead:
189 =head2 Finding out your status
191 The most common git command you will use will probably be
195 This command will produce as output a description of the current state
196 of the repository, including modified files and unignored untracked
197 files, and in addition it will show things like what files have been
198 staged for the next commit, and usually some useful information about
199 how to change things. For instance the following:
203 # Your branch is ahead of 'origin/blead' by 1 commit.
205 # Changes to be committed:
206 # (use "git reset HEAD <file>..." to unstage)
208 # modified: pod/perlrepository.pod
210 # Changed but not updated:
211 # (use "git add <file>..." to update what will be committed)
213 # modified: pod/perlrepository.pod
216 # (use "git add <file>..." to include in what will be committed)
218 # deliberate.untracked
220 This shows that there were changes to this document staged for commit,
221 and that there were further changes in the working directory not yet
222 staged. It also shows that there was an untracked file in the working
223 directory, and as you can see shows how to change all of this. It also
224 shows that there is one commit on the working branch C<blead> which has
225 not been pushed to the C<origin> remote yet. B<NOTE>: that this output
226 is also what you see as a template if you do not provide a message to
229 Assuming that you'd like to commit all the changes you've just made as a
230 a single atomic unit, run this command:
234 (That C<-a> tells git to add every file you've changed to this commit.
235 New files aren't automatically added to your commit when you use C<commit
236 -a> If you want to add files or to commit some, but not all of your
237 changes, have a look at the documentation for C<git add>.)
239 Git will start up your favorite text editor, so that you can craft a
240 commit message for your change. See L</Commit message> below for more
241 information about what makes a good commit message.
243 Once you've finished writing your commit message and exited your editor,
244 git will write your change to disk and tell you something like this:
246 Created commit daf8e63: explain git status and stuff about remotes
247 1 files changed, 83 insertions(+), 3 deletions(-)
250 If you re-run C<git status>, you should see something like this:
254 # Your branch is ahead of 'origin/blead' by 2 commits.
257 # (use "git add <file>..." to include in what will be committed)
259 # deliberate.untracked
260 nothing added to commit but untracked files present (use "git add" to track)
263 When in doubt, before you do anything else, check your status and read
264 it carefully, many questions are answered directly by the git status
267 =head1 Submitting a patch
269 If you have a patch in mind for Perl, you should first get a copy of
272 % git clone git://perl5.git.perl.org/perl.git perl-git
274 Then change into the directory:
278 Alternatively, if you already have a Perl repository, you should ensure
279 that you're on the I<blead> branch, and your repository is up to date:
284 It's preferable to patch against the latest blead version, since this
285 is where new development occurs for all changes other than critical bug
286 fixes. Critical bug fix patches should be made against the relevant
287 maint branches, or should be submitted with a note indicating all the
288 branches where the fix should be applied.
290 Now that we have everything up to date, we need to create a temporary
291 new branch for these changes and switch into it:
293 % git checkout -b orange
295 which is the short form of
298 % git checkout orange
300 Creating a topic branch makes it easier for the maintainers to rebase
301 or merge back into the master blead for a more linear history. If you
302 don't work on a topic branch the maintainer has to manually cherry
303 pick your changes onto blead before they can be applied.
305 That'll get you scolded on perl5-porters, so don't do that. Be
308 Then make your changes. For example, if Leon Brocard changes his name
309 to Orange Brocard, we should change his name in the AUTHORS file:
311 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
313 You can see what files are changed:
317 # Changes to be committed:
318 # (use "git reset HEAD <file>..." to unstage)
323 And you can see the changes:
326 diff --git a/AUTHORS b/AUTHORS
327 index 293dd70..722c93e 100644
330 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
331 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
332 Leif Huhn <leif@hale.dkstat.com>
333 Len Johnson <lenjay@ibm.net>
334 -Leon Brocard <acme@astray.com>
335 +Orange Brocard <acme@astray.com>
336 Les Peters <lpeters@aol.net>
337 Lesley Binks <lesley.binks@gmail.com>
338 Lincoln D. Stein <lstein@cshl.org>
340 Now commit your change locally:
342 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
343 Created commit 6196c1d: Rename Leon Brocard to Orange Brocard
344 1 files changed, 1 insertions(+), 1 deletions(-)
346 You can examine your last commit with:
350 and if you are not happy with either the description or the patch
351 itself you can fix it up by editing the files once more and then issue:
353 % git commit -a --amend
355 Now you should create a patch file for all your local changes:
357 % git format-patch -M origin..
358 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
360 You should now send an email to either perlbug@perl.org or
361 perl5-porters@perl.org with a description of your changes, and include
362 this patch file as an attachment. The perlbug address is preferred,
363 but use perl5-porters for patches intended for discussion.
365 See the next section for how to configure and use git to send these
368 If you want to delete your temporary branch, you may do so with:
371 % git branch -d orange
372 error: The branch 'orange' is not an ancestor of your current HEAD.
373 If you are sure you want to delete it, run 'git branch -D orange'.
374 % git branch -D orange
375 Deleted branch orange.
377 =head2 Using git to send patch emails
379 In your ~/git/perl repository, set the destination email to perl's bug
382 $ git config sendemail.to perlbug@perl.org
384 Or maybe perl5-porters (discussed above):
386 $ git config sendemail.to perl5-porters@perl.org
388 Then you can use git directly to send your patch emails:
390 $ git send-email 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
392 You may need to set some configuration variables for your particular
393 email service provider. For example, to set your global git config to
394 send email via a gmail account:
396 $ git config --global sendemail.smtpserver smtp.gmail.com
397 $ git config --global sendemail.smtpssl 1
398 $ git config --global sendemail.smtpuser YOURUSERNAME@gmail.com
400 With this configuration, you will be prompted for your gmail password
401 when you run 'git send-email'. You can also configure
402 C<sendemail.smtppass> with your password if you don't care about having
403 your password in the .gitconfig file.
405 =head2 A note on derived files
407 Be aware that many files in the distribution are derivative--avoid
408 patching them, because git won't see the changes to them, and the build
409 process will overwrite them. Patch the originals instead. Most
410 utilities (like perldoc) are in this category, i.e. patch
411 F<utils/perldoc.PL> rather than F<utils/perldoc>. Similarly, don't create
412 patches for files under $src_root/ext from their copies found in
413 $install_root/lib. If you are unsure about the proper location of a
414 file that may have gotten copied while building the source
415 distribution, consult the C<MANIFEST>.
417 As a special case, several files are regenerated by 'make regen' if
418 your patch alters C<embed.fnc>. These are needed for compilation, but
419 are included in the distribution so that you can build perl without
420 needing another perl to generate the files. You must test with these
421 regenerated files, but it is preferred that you instead note that
422 'make regen is needed' in both the email and the commit message, and
423 submit your patch without them. If you're submitting a series of
424 patches, it might be best to submit the regenerated changes
425 immediately after the source-changes that caused them, so as to have
426 as little effect as possible on the bisectability of your patchset.
430 What should we recommend about binary files now? Do we need anything?
432 =head2 Getting your patch accepted
434 If you are submitting a code patch there are several things that
441 As you craft each patch you intend to submit to the Perl core, it's
442 important to write a good commit message.
444 The first line of the commit message should be a short description and
445 should skip the full stop. It should be no longer than the subject
446 line of an E-Mail, 50 characters being a good rule of thumb.
448 A lot of Git tools (Gitweb, GitHub, git log --pretty=oneline, ..) will
449 only display the first line (cut off at 50 characters) when presenting
452 The commit message should include description of the problem that the
453 patch corrects or new functionality that the patch adds.
455 As a general rule of thumb, your commit message should let a programmer
456 with a reasonable familiarity with the Perl core quickly understand what
457 you were trying to do, how you were trying to do it and why the change
464 Your commit message should describe what part of the Perl core you're
465 changing and what you expect your patch to do.
469 Perhaps most importantly, your commit message should describe why the
470 change you are making is important. When someone looks at your change
471 in six months or six years, your intent should be clear. If you're
472 deprecating a feature with the intent of later simplifying another bit
473 of code, say so. If you're fixing a performance problem or adding a new
474 feature to support some other bit of the core, mention that.
478 While it's not necessary for documentation changes, new tests or
479 trivial patches, it's often worth explaining how your change works.
480 Even if it's clear to you today, it may not be clear to a porter next
485 A commit message isn't intended to take the place of comments in your
486 code. Commit messages should describe the change you made, while code
487 comments should describe the current state of the code. If you've just
488 implemented a new feature, complete with doc, tests and well-commented
489 code, a brief commit message will often suffice. If, however, you've
490 just changed a single character deep in the parser or lexer, you might
491 need to write a small novel to ensure that future readers understand
492 what you did and why you did it.
494 =item Comments, Comments, Comments
496 Be sure to adequately comment your code. While commenting every line
497 is unnecessary, anything that takes advantage of side effects of
498 operators, that creates changes that will be felt outside of the
499 function being patched, or that others may find confusing should be
500 documented. If you are going to err, it is better to err on the side
501 of adding too many comments than too few.
505 In general, please follow the particular style of the code you are
508 In particular, follow these general guidelines for patching Perl
511 8-wide tabs (no exceptions!)
512 4-wide indents for code, 2-wide indents for nested CPP #defines
513 try hard not to exceed 79-columns
515 uncuddled elses and "K&R" style for indenting control constructs
516 no C++ style (//) comments
517 mark places that need to be revisited with XXX (and revisit often!)
518 opening brace lines up with "if" when conditional spans multiple
519 lines; should be at end-of-line otherwise
520 in function definitions, name starts in column 0 (return value is on
522 single space after keywords that are followed by parens, no space
523 between function name and following paren
524 avoid assignments in conditionals, but if they're unavoidable, use
525 extra paren, e.g. "if (a && (b = c)) ..."
526 "return foo;" rather than "return(foo);"
527 "if (!foo) ..." rather than "if (foo == FALSE) ..." etc.
531 If your patch changes code (rather than just changing documentation) you
532 should also include one or more test cases which illustrate the bug you're
533 fixing or validate the new functionality you're adding. In general,
534 you should update an existing test file rather than create a new one.
536 Your testsuite additions should generally follow these guidelines
537 (courtesy of Gurusamy Sarathy <gsar@activestate.com>):
539 Know what you're testing. Read the docs, and the source.
540 Tend to fail, not succeed.
541 Interpret results strictly.
542 Use unrelated features (this will flush out bizarre interactions).
543 Use non-standard idioms (otherwise you are not testing TIMTOWTDI).
544 Avoid using hardcoded test numbers whenever possible (the
545 EXPECTED/GOT found in t/op/tie.t is much more maintainable,
546 and gives better failure reports).
547 Give meaningful error messages when a test fails.
548 Avoid using qx// and system() unless you are testing for them. If you
549 do use them, make sure that you cover _all_ perl platforms.
550 Unlink any temporary files you create.
551 Promote unforeseen warnings to errors with $SIG{__WARN__}.
552 Be sure to use the libraries and modules shipped with the version
553 being tested, not those that were already installed.
554 Add comments to the code explaining what you are testing for.
555 Make updating the '1..42' string unnecessary. Or make sure that
557 Test _all_ behaviors of a given operator, library, or function:
558 - All optional arguments
559 - Return values in various contexts (boolean, scalar, list, lvalue)
560 - Use both global and lexical variables
561 - Don't forget the exceptional, pathological cases.
565 =head1 Accepting a patch
567 If you have received a patch file generated using the above section,
568 you should try out the patch.
570 First we need to create a temporary new branch for these changes and
573 % git checkout -b experimental
575 Patches that were formatted by C<git format-patch> are applied with
578 % git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
579 Applying Rename Leon Brocard to Orange Brocard
581 If just a raw diff is provided, it is also possible use this two-step
584 % git apply bugfix.diff
585 % git commit -a -m "Some fixing" --author="That Guy <that.guy@internets.com>"
587 Now we can inspect the change:
590 commit b1b3dab48344cff6de4087efca3dbd63548ab5e2
591 Author: Leon Brocard <acme@astray.com>
592 Date: Fri Dec 19 17:02:59 2008 +0000
594 Rename Leon Brocard to Orange Brocard
596 diff --git a/AUTHORS b/AUTHORS
597 index 293dd70..722c93e 100644
600 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
601 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
602 Leif Huhn <leif@hale.dkstat.com>
603 Len Johnson <lenjay@ibm.net>
604 -Leon Brocard <acme@astray.com>
605 +Orange Brocard <acme@astray.com>
606 Les Peters <lpeters@aol.net>
607 Lesley Binks <lesley.binks@gmail.com>
608 Lincoln D. Stein <lstein@cshl.org>
610 If you are a committer to Perl and you think the patch is good, you can
611 then merge it into blead then push it out to the main repository:
614 % git merge experimental
617 If you want to delete your temporary branch, you may do so with:
620 % git branch -d experimental
621 error: The branch 'experimental' is not an ancestor of your current HEAD.
622 If you are sure you want to delete it, run 'git branch -D experimental'.
623 % git branch -D experimental
624 Deleted branch experimental.
626 =head1 Cleaning a working directory
628 The command C<git clean> can with varying arguments be used as a
629 replacement for C<make clean>.
631 To reset your working directory to a pristine condition you can do:
635 However, be aware this will delete ALL untracked content. You can use
639 to remove all ignored untracked files, such as build and test
640 byproduct, but leave any manually created files alone.
642 If you only want to cancel some uncommitted edits, you can use C<git
643 checkout> and give it a list of files to be reverted, or C<git checkout
644 -f> to revert them all.
646 If you want to cancel one or several commits, you can use C<git reset>.
650 C<git> provides a built-in way to determine, with a binary search in
651 the history, which commit should be blamed for introducing a given bug.
653 Suppose that we have a script F<~/testcase.pl> that exits with C<0>
654 when some behaviour is correct, and with C<1> when it's faulty. You need
655 an helper script that automates building C<perl> and running the
662 # If you get './makedepend: 1: Syntax error: Unterminated quoted
663 # string' when bisecting versions of perl older than 5.9.5 this hack
664 # will work around the bug in makedepend.SH which was fixed in
665 # version 96a8704c. Make sure to comment out `git checkout makedepend.SH'
667 git show blead:makedepend.SH > makedepend.SH
669 # If you can use ccache, add -Dcc=ccache\ gcc -Dld=gcc to the Configure line
670 # if Encode is not needed for the test, you can speed up the bisect by
671 # excluding it from the runs with -Dnoextensions=Encode
672 sh Configure -des -Dusedevel -Doptimize="-g"
673 test -f config.sh || exit 125
674 # Correct makefile for newer GNU gcc
675 perl -ni -we 'print unless /<(?:built-in|command)/' makefile x2p/makefile
676 # if you just need miniperl, replace test_prep with miniperl
678 [ -x ./perl ] || exit 125
679 ./perl -Ilib ~/testcase.pl
681 [ $ret -gt 127 ] && ret=127
682 # git checkout makedepend.SH
686 This script may return C<125> to indicate that the corresponding commit
687 should be skipped. Otherwise, it returns the status of
690 You first enter in bisect mode with:
694 For example, if the bug is present on C<HEAD> but wasn't in 5.10.0,
695 C<git> will learn about this when you enter:
698 % git bisect good perl-5.10.0
699 Bisecting: 853 revisions left to test after this
701 This results in checking out the median commit between C<HEAD> and
702 C<perl-5.10.0>. You can then run the bisecting process with:
704 % git bisect run ~/run
706 When the first bad commit is isolated, C<git bisect> will tell you so:
708 ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit
709 commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5
710 Author: Dave Mitchell <davem@fdisolutions.com>
711 Date: Sat Feb 9 14:56:23 2008 +0000
713 [perl #49472] Attributes + Unknown Error
718 You can peek into the bisecting process with C<git bisect log> and
719 C<git bisect visualize>. C<git bisect reset> will get you out of bisect
722 Please note that the first C<good> state must be an ancestor of the
723 first C<bad> state. If you want to search for the commit that I<solved>
724 some bug, you have to negate your test case (i.e. exit with C<1> if OK
725 and C<0> if not) and still mark the lower bound as C<good> and the
726 upper as C<bad>. The "first bad commit" has then to be understood as
727 the "first commit where the bug is solved".
729 C<git help bisect> has much more information on how you can tweak your
732 =head1 Submitting a patch via GitHub
734 GitHub is a website that makes it easy to fork and publish projects
735 with Git. First you should set up a GitHub account and log in.
737 Perl's git repository is mirrored on GitHub at this page:
739 http://github.com/mirrors/perl/tree/blead
741 Visit the page and click the "fork" button. This clones the Perl git
742 repository for you and provides you with "Your Clone URL" from which
745 % git clone git@github.com:USERNAME/perl.git perl-github
747 The same patch as above, using github might look like this:
750 % git remote add upstream git://perl5.git.perl.org/perl.git
751 % git pull upstream blead
752 % git checkout -b orange
753 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
754 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
755 % git push origin orange
757 The orange branch has been pushed to GitHub, so you should now send an
758 email (see L</Submitting a patch>) with a description of your changes
759 and the following information:
761 http://github.com/USERNAME/perl/tree/orange
762 git://github.com/USERNAME/perl.git branch orange
764 =head1 Merging from a branch via GitHub
766 If someone has provided a branch via GitHub and you are a committer,
767 you should use the following in your perl-ssh directory:
769 % git remote add avar git://github.com/avar/perl.git
772 Now you can see the differences between the branch and blead:
774 % git diff avar/orange
776 And you can see the commits:
778 % git log avar/orange
780 If you approve of a specific commit, you can cherry pick it:
782 % git cherry-pick 0c24b290ae02b2ab3304f51d5e11e85eb3659eae
784 Or you could just merge the whole branch if you like it all:
786 % git merge avar/orange
788 And then push back to the repository:
793 =head1 Topic branches and rewriting history
795 Individual committers should create topic branches under
796 B<yourname>/B<some_descriptive_name>. Other committers should check
797 with a topic branch's creator before making any change to it.
799 The simplest way to create a remote topic branch that works on all
800 versions of git is to push the current head as a new branch on the
801 remote, then check it out locally:
803 $ branch="$yourname/$some_descriptive_name"
804 $ git push origin HEAD:$branch
805 $ git checkout -b $branch origin/$branch
807 Users of git 1.7 or newer can do it in a more obvious manner:
809 $ branch="$yourname/$some_descriptive_name"
810 $ git checkout -b $branch
811 $ git push origin -u $branch
813 If you are not the creator of B<yourname>/B<some_descriptive_name>, you
814 might sometimes find that the original author has edited the branch's
815 history. There are lots of good reasons for this. Sometimes, an author
816 might simply be rebasing the branch onto a newer source point.
817 Sometimes, an author might have found an error in an early commit which
818 they wanted to fix before merging the branch to blead.
820 Currently the master repository is configured to forbid
821 non-fast-forward merges. This means that the branches within can not
822 be rebased and pushed as a single step.
824 The only way you will ever be allowed to rebase or modify the history
825 of a pushed branch is to delete it and push it as a new branch under
826 the same name. Please think carefully about doing this. It may be
827 better to sequentially rename your branches so that it is easier for
828 others working with you to cherry-pick their local changes onto the new
829 version. (XXX: needs explanation).
831 If you want to rebase a personal topic branch, you will have to delete
832 your existing topic branch and push as a new version of it. You can do
833 this via the following formula (see the explanation about C<refspec>'s
834 in the git push documentation for details) after you have rebased your
838 $ git checkout $user/$topic
840 $ git rebase origin/blead
842 # then "delete-and-push"
843 $ git push origin :$user/$topic
844 $ git push origin $user/$topic
846 B<NOTE:> it is forbidden at the repository level to delete any of the
847 "primary" branches. That is any branch matching
848 C<m!^(blead|maint|perl)!>. Any attempt to do so will result in git
849 producing an error like this:
851 $ git push origin :blead
852 *** It is forbidden to delete blead/maint branches in this repository
853 error: hooks/update exited with error code 1
854 error: hook declined to update refs/heads/blead
855 To ssh://perl5.git.perl.org/perl
856 ! [remote rejected] blead (hook declined)
857 error: failed to push some refs to 'ssh://perl5.git.perl.org/perl'
859 As a matter of policy we do B<not> edit the history of the blead and
860 maint-* branches. If a typo (or worse) sneaks into a commit to blead or
861 maint-*, we'll fix it in another commit. The only types of updates
862 allowed on these branches are "fast-forward's", where all history is
865 Annotated tags in the canonical perl.git repository will never be
866 deleted or modified. Think long and hard about whether you want to push
867 a local tag to perl.git before doing so. (Pushing unannotated tags is
870 =head1 Committing to maintenance versions
872 Maintenance versions should only be altered to add critical bug
873 fixes, see L<perlpolicy>.
875 To commit to a maintenance version of perl, you need to create a local
878 % git checkout --track -b maint-5.005 origin/maint-5.005
880 This creates a local branch named C<maint-5.005>, which tracks the
881 remote branch C<origin/maint-5.005>. Then you can pull, commit, merge
884 You can also cherry-pick commits from blead and another branch, by
885 using the C<git cherry-pick> command. It is recommended to use the
886 B<-x> option to C<git cherry-pick> in order to record the SHA1 of the
887 original commit in the new commit message.
891 The perl history contains one mistake which was not caught in the
892 conversion: a merge was recorded in the history between blead and
893 maint-5.10 where no merge actually occurred. Due to the nature of git,
894 this is now impossible to fix in the public repository. You can remove
895 this mis-merge locally by adding the following line to your
896 C<.git/info/grafts> file:
898 296f12bbbbaa06de9be9d09d3dcf8f4528898a49 434946e0cb7a32589ed92d18008aaa1d88515930
900 It is particularly important to have this graft line if any bisecting
901 is done in the area of the "merge" in question.
909 The git documentation, accessible via the C<git help> command
913 L<perlpolicy> - Perl core development policy