1PERLGIT(1) Perl Programmers Reference Guide PERLGIT(1)
2
6 perlgit - Detailed information about git and the Perl repository
7
9 This document provides details on using git to develop Perl. If you are
10 just interested in working on a quick patch, see perlhack first. This
11 document is intended for people who are regular contributors to Perl,
12 including those with write access to the git repository.
13
15 All of Perl's source code is kept centrally in a Git repository at
16 github.com.
17 You can make a read-only clone of the repository by running:
19 % git clone git@github.com:Perl/perl5.git perl
21 If you cannot use that for firewall reasons, you can also clone via
23 http:
24 % git clone https://github.com/Perl/perl5.git perl
26
28 Once you have changed into the repository directory, you can inspect
29 it. After a clone the repository will contain a single local branch,
30 which will be the current branch as well, as indicated by the asterisk.
31 % git branch
33 * blead
34 Using the -a switch to "branch" will also show the remote tracking
36 branches in the repository:
37 % git branch -a
39 * blead
40 origin/HEAD
41 origin/blead
42 ...
43 The branches that begin with "origin" correspond to the "git remote"
45 that you cloned from (which is named "origin"). Each branch on the
46 remote will be exactly tracked by these branches. You should NEVER do
47 work on these remote tracking branches. You only ever do work in a
48 local branch. Local branches can be configured to automerge (on pull)
49 from a designated remote tracking branch. This is the case with the
50 default branch "blead" which will be configured to merge from the
51 remote tracking branch "origin/blead".
52 You can see recent commits:
54 % git log
56 And pull new changes from the repository, and update your local
58 repository (must be clean first)
59 % git pull
61 Assuming we are on the branch "blead" immediately after a pull, this
63 command would be more or less equivalent to:
64 % git fetch
66 % git merge origin/blead
67 In fact if you want to update your local repository without touching
69 your working directory you do:
70 % git fetch
72 And if you want to update your remote-tracking branches for all defined
74 remotes simultaneously you can do
75 % git remote update
77 Neither of these last two commands will update your working directory,
79 however both will update the remote-tracking branches in your
80 repository.
81 To make a local branch of a remote branch:
83 % git checkout -b maint-5.10 origin/maint-5.10
85 To switch back to blead:
87 % git checkout blead
89 Finding out your status
91 The most common git command you will use will probably be
92 % git status
94 This command will produce as output a description of the current state
96 of the repository, including modified files and unignored untracked
97 files, and in addition it will show things like what files have been
98 staged for the next commit, and usually some useful information about
99 how to change things. For instance the following:
100 % git status
102 On branch blead
103 Your branch is ahead of 'origin/blead' by 1 commit.
104 Changes to be committed:
106 (use "git reset HEAD <file>..." to unstage)
107 modified: pod/perlgit.pod
109 Changes not staged for commit:
111 (use "git add <file>..." to update what will be committed)
112 (use "git checkout -- <file>..." to discard changes in working
113 directory)
114 modified: pod/perlgit.pod
116 Untracked files:
118 (use "git add <file>..." to include in what will be committed)
119 deliberate.untracked
121 This shows that there were changes to this document staged for commit,
123 and that there were further changes in the working directory not yet
124 staged. It also shows that there was an untracked file in the working
125 directory, and as you can see shows how to change all of this. It also
126 shows that there is one commit on the working branch "blead" which has
127 not been pushed to the "origin" remote yet. NOTE: This output is also
128 what you see as a template if you do not provide a message to "git
129 commit".
130 Patch workflow
132 First, please read perlhack for details on hacking the Perl core. That
133 document covers many details on how to create a good patch.
134 If you already have a Perl repository, you should ensure that you're on
136 the blead branch, and your repository is up to date:
137 % git checkout blead
139 % git pull
140 It's preferable to patch against the latest blead version, since this
142 is where new development occurs for all changes other than critical bug
143 fixes. Critical bug fix patches should be made against the relevant
144 maint branches, or should be submitted with a note indicating all the
145 branches where the fix should be applied.
146 Now that we have everything up to date, we need to create a temporary
148 new branch for these changes and switch into it:
149 % git checkout -b orange
151 which is the short form of
153 % git branch orange
155 % git checkout orange
156 Creating a topic branch makes it easier for the maintainers to rebase
158 or merge back into the master blead for a more linear history. If you
159 don't work on a topic branch the maintainer has to manually cherry pick
160 your changes onto blead before they can be applied.
161 That'll get you scolded on perl5-porters, so don't do that. Be Awesome.
163 Then make your changes. For example, if Leon Brocard changes his name
165 to Orange Brocard, we should change his name in the AUTHORS file:
166 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
168 You can see what files are changed:
170 % git status
172 On branch orange
173 Changes to be committed:
174 (use "git reset HEAD <file>..." to unstage)
175 modified: AUTHORS
177 And you can see the changes:
179 % git diff
181 diff --git a/AUTHORS b/AUTHORS
182 index 293dd70..722c93e 100644
183 --- a/AUTHORS
184 +++ b/AUTHORS
185 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
186 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
187 Leif Huhn <leif@hale.dkstat.com>
188 Len Johnson <lenjay@ibm.net>
189 -Leon Brocard <acme@astray.com>
190 +Orange Brocard <acme@astray.com>
191 Les Peters <lpeters@aol.net>
192 Lesley Binks <lesley.binks@gmail.com>
193 Lincoln D. Stein <lstein@cshl.org>
194 Now commit your change locally:
196 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
198 Created commit 6196c1d: Rename Leon Brocard to Orange Brocard
199 1 files changed, 1 insertions(+), 1 deletions(-)
200 The "-a" option is used to include all files that git tracks that you
202 have changed. If at this time, you only want to commit some of the
203 files you have worked on, you can omit the "-a" and use the command
204 "git add FILE ..." before doing the commit. "git add --interactive"
205 allows you to even just commit portions of files instead of all the
206 changes in them.
207 The "-m" option is used to specify the commit message. If you omit it,
209 git will open a text editor for you to compose the message
210 interactively. This is useful when the changes are more complex than
211 the sample given here, and, depending on the editor, to know that the
212 first line of the commit message doesn't exceed the 50 character legal
213 maximum. See "Commit message" in perlhack for more information about
214 what makes a good commit message.
215 Once you've finished writing your commit message and exited your
217 editor, git will write your change to disk and tell you something like
218 this:
219 Created commit daf8e63: explain git status and stuff about remotes
221 1 files changed, 83 insertions(+), 3 deletions(-)
222 If you re-run "git status", you should see something like this:
224 % git status
226 On branch orange
227 Untracked files:
228 (use "git add <file>..." to include in what will be committed)
229 deliberate.untracked
231 nothing added to commit but untracked files present (use "git add" to
233 track)
234 When in doubt, before you do anything else, check your status and read
236 it carefully, many questions are answered directly by the git status
237 output.
238 You can examine your last commit with:
240 % git show HEAD
242 and if you are not happy with either the description or the patch
244 itself you can fix it up by editing the files once more and then issue:
245 % git commit -a --amend
247 Now, create a fork on GitHub to push your branch to, and add it as a
249 remote if you haven't already, as described in the GitHub documentation
250 at <https://help.github.com/en/articles/working-with-forks>:
251 % git remote add fork git@github.com:MyUser/perl5.git
253 And push the branch to your fork:
255 % git push -u fork orange
257 You should now submit a Pull Request (PR) on GitHub from the new branch
259 to blead. For more information, see the GitHub documentation at
260 <https://help.github.com/en/articles/creating-a-pull-request-from-a-fork>.
261 You can also send patch files to perl5-porters@perl.org
263 <mailto:perl5-porters@perl.org> directly if the patch is not ready to
264 be applied, but intended for discussion.
265 To create a patch file for all your local changes:
267 % git format-patch -M blead..
269 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
270 Or for a lot of changes, e.g. from a topic branch:
272 % git format-patch --stdout -M blead.. > topic-branch-changes.patch
274 If you want to delete your temporary branch, you may do so with:
276 % git checkout blead
278 % git branch -d orange
279 error: The branch 'orange' is not an ancestor of your current HEAD.
280 If you are sure you want to delete it, run 'git branch -D orange'.
281 % git branch -D orange
282 Deleted branch orange.
283 A note on derived files
285 Be aware that many files in the distribution are derivative--avoid
286 patching them, because git won't see the changes to them, and the build
287 process will overwrite them. Patch the originals instead. Most
288 utilities (like perldoc) are in this category, i.e. patch
289 utils/perldoc.PL rather than utils/perldoc. Similarly, don't create
290 patches for files under $src_root/ext from their copies found in
291 $install_root/lib. If you are unsure about the proper location of a
292 file that may have gotten copied while building the source
293 distribution, consult the MANIFEST.
294 Cleaning a working directory
296 The command "git clean" can with varying arguments be used as a
297 replacement for "make clean".
298 To reset your working directory to a pristine condition you can do:
300 % git clean -dxf
302 However, be aware this will delete ALL untracked content. You can use
304 % git clean -Xf
306 to remove all ignored untracked files, such as build and test
308 byproduct, but leave any manually created files alone.
309 If you only want to cancel some uncommitted edits, you can use "git
311 checkout" and give it a list of files to be reverted, or "git checkout
312 -f" to revert them all.
313 If you want to cancel one or several commits, you can use "git reset".
315 Bisecting
317 "git" provides a built-in way to determine which commit should be
318 blamed for introducing a given bug. "git bisect" performs a binary
319 search of history to locate the first failing commit. It is fast,
320 powerful and flexible, but requires some setup and to automate the
321 process an auxiliary shell script is needed.
322 The core provides a wrapper program, Porting/bisect.pl, which attempts
324 to simplify as much as possible, making bisecting as simple as running
325 a Perl one-liner. For example, if you want to know when this became an
326 error:
327 perl -e 'my $a := 2'
329 you simply run this:
331 .../Porting/bisect.pl -e 'my $a := 2;'
333 Using Porting/bisect.pl, with one command (and no other files) it's
335 easy to find out
336 • Which commit caused this example code to break?
338 • Which commit caused this example code to start working?
340 • Which commit added the first file to match this regex?
342 • Which commit removed the last file to match this regex?
344 usually without needing to know which versions of perl to use as start
346 and end revisions, as Porting/bisect.pl automatically searches to find
347 the earliest stable version for which the test case passes. Run
348 "Porting/bisect.pl --help" for the full documentation, including how to
349 set the "Configure" and build time options.
350 If you require more flexibility than Porting/bisect.pl has to offer,
352 you'll need to run "git bisect" yourself. It's most useful to use "git
353 bisect run" to automate the building and testing of perl revisions. For
354 this you'll need a shell script for "git" to call to test a particular
355 revision. An example script is Porting/bisect-example.sh, which you
356 should copy outside of the repository, as the bisect process will reset
357 the state to a clean checkout as it runs. The instructions below assume
358 that you copied it as ~/run and then edited it as appropriate.
359 You first enter in bisect mode with:
361 % git bisect start
363 For example, if the bug is present on "HEAD" but wasn't in 5.10.0,
365 "git" will learn about this when you enter:
366 % git bisect bad
368 % git bisect good perl-5.10.0
369 Bisecting: 853 revisions left to test after this
370 This results in checking out the median commit between "HEAD" and
372 "perl-5.10.0". You can then run the bisecting process with:
373 % git bisect run ~/run
375 When the first bad commit is isolated, "git bisect" will tell you so:
377 ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit
379 commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5
380 Author: Dave Mitchell <davem@fdisolutions.com>
381 Date: Sat Feb 9 14:56:23 2008 +0000
382 [perl #49472] Attributes + Unknown Error
384 ...
385 bisect run success
387 You can peek into the bisecting process with "git bisect log" and "git
389 bisect visualize". "git bisect reset" will get you out of bisect mode.
390 Please note that the first "good" state must be an ancestor of the
392 first "bad" state. If you want to search for the commit that solved
393 some bug, you have to negate your test case (i.e. exit with 1 if OK and
394 0 if not) and still mark the lower bound as "good" and the upper as
395 "bad". The "first bad commit" has then to be understood as the "first
396 commit where the bug is solved".
397 "git help bisect" has much more information on how you can tweak your
399 binary searches.
400 Following bisection you may wish to configure, build and test perl at
402 commits identified by the bisection process. Sometimes, particularly
403 with older perls, "make" may fail during this process. In this case
404 you may be able to patch the source code at the older commit point. To
405 do so, please follow the suggestions provided in "Building perl at
406 older commits" in perlhack.
407 Topic branches and rewriting history
409 Individual committers should create topic branches under
410 yourname/some_descriptive_name:
411 % branch="$yourname/$some_descriptive_name"
413 % git checkout -b $branch
414 ... do local edits, commits etc ...
415 % git push origin -u $branch
416 Should you be stuck with an ancient version of git (prior to 1.7), then
418 "git push" will not have the "-u" switch, and you have to replace the
419 last step with the following sequence:
420 % git push origin $branch:refs/heads/$branch
422 % git config branch.$branch.remote origin
423 % git config branch.$branch.merge refs/heads/$branch
424 If you want to make changes to someone else's topic branch, you should
426 check with its creator before making any change to it.
427 You might sometimes find that the original author has edited the
429 branch's history. There are lots of good reasons for this. Sometimes,
430 an author might simply be rebasing the branch onto a newer source
431 point. Sometimes, an author might have found an error in an early
432 commit which they wanted to fix before merging the branch to blead.
433 Currently the master repository is configured to forbid non-fast-
435 forward merges. This means that the branches within can not be rebased
436 and pushed as a single step.
437 The only way you will ever be allowed to rebase or modify the history
439 of a pushed branch is to delete it and push it as a new branch under
440 the same name. Please think carefully about doing this. It may be
441 better to sequentially rename your branches so that it is easier for
442 others working with you to cherry-pick their local changes onto the new
443 version. (XXX: needs explanation).
444 If you want to rebase a personal topic branch, you will have to delete
446 your existing topic branch and push as a new version of it. You can do
447 this via the following formula (see the explanation about "refspec"'s
448 in the git push documentation for details) after you have rebased your
449 branch:
450 # first rebase
452 % git checkout $user/$topic
453 % git fetch
454 % git rebase origin/blead
455 # then "delete-and-push"
457 % git push origin :$user/$topic
458 % git push origin $user/$topic
459 NOTE: it is forbidden at the repository level to delete any of the
461 "primary" branches. That is any branch matching
462 "m!^(blead|maint|perl)!". Any attempt to do so will result in git
463 producing an error like this:
464 % git push origin :blead
466 *** It is forbidden to delete blead/maint branches in this repository
467 error: hooks/update exited with error code 1
468 error: hook declined to update refs/heads/blead
469 To ssh://perl5.git.perl.org/perl
470 ! [remote rejected] blead (hook declined)
471 error: failed to push some refs to 'ssh://perl5.git.perl.org/perl'
472 As a matter of policy we do not edit the history of the blead and
474 maint-* branches. If a typo (or worse) sneaks into a commit to blead or
475 maint-*, we'll fix it in another commit. The only types of updates
476 allowed on these branches are "fast-forwards", where all history is
477 preserved.
478 Annotated tags in the canonical perl.git repository will never be
480 deleted or modified. Think long and hard about whether you want to push
481 a local tag to perl.git before doing so. (Pushing simple tags is not
482 allowed.)
483 Grafts
485 The perl history contains one mistake which was not caught in the
486 conversion: a merge was recorded in the history between blead and
487 maint-5.10 where no merge actually occurred. Due to the nature of git,
488 this is now impossible to fix in the public repository. You can remove
489 this mis-merge locally by adding the following line to your
490 ".git/info/grafts" file:
491 296f12bbbbaa06de9be9d09d3dcf8f4528898a49 434946e0cb7a32589ed92d18008aaa1d88515930
493 It is particularly important to have this graft line if any bisecting
495 is done in the area of the "merge" in question.
496
498 Once you have write access, you will need to modify the URL for the
499 origin remote to enable pushing. Edit .git/config with the
500 git-config(1) command:
501 % git config remote.origin.url git@github.com:Perl/perl5.git
503 You can also set up your user name and e-mail address. Most people do
505 this once globally in their ~/.gitconfig by doing something like:
506 % git config --global user.name "Ævar Arnfjörð Bjarmason"
508 % git config --global user.email avarab@gmail.com
509 However, if you'd like to override that just for perl, execute
511 something like the following in perl:
512 % git config user.email avar@cpan.org
514 It is also possible to keep "origin" as a git remote, and add a new
516 remote for ssh access:
517 % git remote add camel git@github.com:Perl/perl5.git
519 This allows you to update your local repository by pulling from
521 "origin", which is faster and doesn't require you to authenticate, and
522 to push your changes back with the "camel" remote:
523 % git fetch camel
525 % git push camel
526 The "fetch" command just updates the "camel" refs, as the objects
528 themselves should have been fetched when pulling from "origin".
529 Working with Github pull requests
531 Pull requests typically originate from outside of the "Perl/perl.git"
532 repository, so if you want to test or work with it locally a vanilla
533 "git fetch" from the "Perl/perl5.git" repository won't fetch it.
534 However Github does provide a mechanism to fetch a pull request to a
536 local branch. They are available on Github remotes under "pull/", so
537 you can use "git fetch pull/PRID/head:localname" to make a local copy.
538 eg. to fetch pull request 9999 to the local branch "local-branch-name"
539 run:
540 git fetch origin pull/9999/head:local-branch-name
542 and then:
544 git checkout local-branch-name
546 Note: this branch is not rebased on "blead", so instead of the checkout
548 above, you might want:
549 git rebase origin/blead local-branch-name
551 which rebases "local-branch-name" on "blead", and checks it out.
553 Alternatively you can configure the remote to fetch all pull requests
555 as remote-tracking branches. To do this edit the remote in
556 .git/config, for example if your github remote is "origin" you'd have:
557 [remote "origin"]
559 url = git@github.com:/Perl/perl5.git
560 fetch = +refs/heads/*:refs/remotes/origin/*
561 Add a line to map the remote pull request branches to remote-tracking
563 branches:
564 [remote "origin"]
566 url = git@github.com:/Perl/perl5.git
567 fetch = +refs/heads/*:refs/remotes/origin/*
568 fetch = +refs/pull/*/head:refs/remotes/origin/pull/*
569 and then do a fetch as normal:
571 git fetch origin
573 This will create a remote-tracking branch for every pull request,
575 including closed requests.
576 To remove those remote-tracking branches, remove the line added above
578 and prune:
579 git fetch -p origin # or git remote prune origin
581 Accepting a patch
583 If you have received a patch file generated using the above section,
584 you should try out the patch.
585 First we need to create a temporary new branch for these changes and
587 switch into it:
588 % git checkout -b experimental
590 Patches that were formatted by "git format-patch" are applied with "git
592 am":
593 % git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
595 Applying Rename Leon Brocard to Orange Brocard
596 Note that some UNIX mail systems can mess with text attachments
598 containing 'From '. This will fix them up:
599 % perl -pi -e's/^>From /From /' \
601 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
602 If just a raw diff is provided, it is also possible use this two-step
604 process:
605 % git apply bugfix.diff
607 % git commit -a -m "Some fixing" \
608 --author="That Guy <that.guy@internets.com>"
609 Now we can inspect the change:
611 % git show HEAD
613 commit b1b3dab48344cff6de4087efca3dbd63548ab5e2
614 Author: Leon Brocard <acme@astray.com>
615 Date: Fri Dec 19 17:02:59 2008 +0000
616 Rename Leon Brocard to Orange Brocard
618 diff --git a/AUTHORS b/AUTHORS
620 index 293dd70..722c93e 100644
621 --- a/AUTHORS
622 +++ b/AUTHORS
623 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
624 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
625 Leif Huhn <leif@hale.dkstat.com>
626 Len Johnson <lenjay@ibm.net>
627 -Leon Brocard <acme@astray.com>
628 +Orange Brocard <acme@astray.com>
629 Les Peters <lpeters@aol.net>
630 Lesley Binks <lesley.binks@gmail.com>
631 Lincoln D. Stein <lstein@cshl.org>
632 If you are a committer to Perl and you think the patch is good, you can
634 then merge it into blead then push it out to the main repository:
635 % git checkout blead
637 % git merge experimental
638 % git push origin blead
639 If you want to delete your temporary branch, you may do so with:
641 % git checkout blead
643 % git branch -d experimental
644 error: The branch 'experimental' is not an ancestor of your current
645 HEAD. If you are sure you want to delete it, run 'git branch -D
646 experimental'.
647 % git branch -D experimental
648 Deleted branch experimental.
649 Committing to blead
651 The 'blead' branch will become the next production release of Perl.
652 Before pushing any local change to blead, it's incredibly important
654 that you do a few things, lest other committers come after you with
655 pitchforks and torches:
656 • Make sure you have a good commit message. See "Commit message" in
658 perlhack for details.
659 • Run the test suite. You might not think that one typo fix would
661 break a test file. You'd be wrong. Here's an example of where not
662 running the suite caused problems. A patch was submitted that added
663 a couple of tests to an existing .t. It couldn't possibly affect
664 anything else, so no need to test beyond the single affected .t,
665 right? But, the submitter's email address had changed since the
666 last of their submissions, and this caused other tests to fail.
667 Running the test target given in the next item would have caught
668 this problem.
669 • If you don't run the full test suite, at least "make test_porting".
671 This will run basic sanity checks. To see which sanity checks, have
672 a look in t/porting.
673 • If you make any changes that affect miniperl or core routines that
675 have different code paths for miniperl, be sure to run "make
676 minitest". This will catch problems that even the full test suite
677 will not catch because it runs a subset of tests under miniperl
678 rather than perl.
679 On merging and rebasing
681 Simple, one-off commits pushed to the 'blead' branch should be simple
682 commits that apply cleanly. In other words, you should make sure your
683 work is committed against the current position of blead, so that you
684 can push back to the master repository without merging.
685 Sometimes, blead will move while you're building or testing your
687 changes. When this happens, your push will be rejected with a message
688 like this:
689 To ssh://perl5.git.perl.org/perl.git
691 ! [rejected] blead -> blead (non-fast-forward)
692 error: failed to push some refs to 'ssh://perl5.git.perl.org/perl.git'
693 To prevent you from losing history, non-fast-forward updates were
694 rejected Merge the remote changes (e.g. 'git pull') before pushing
695 again. See the 'Note about fast-forwards' section of 'git push --help'
696 for details.
697 When this happens, you can just rebase your work against the new
699 position of blead, like this (assuming your remote for the master
700 repository is "p5p"):
701 % git fetch p5p
703 % git rebase p5p/blead
704 You will see your commits being re-applied, and you will then be able
706 to push safely. More information about rebasing can be found in the
707 documentation for the git-rebase(1) command.
708 For larger sets of commits that only make sense together, or that would
710 benefit from a summary of the set's purpose, you should use a merge
711 commit. You should perform your work on a topic branch, which you
712 should regularly rebase against blead to ensure that your code is not
713 broken by blead moving. When you have finished your work, please
714 perform a final rebase and test. Linear history is something that gets
715 lost with every commit on blead, but a final rebase makes the history
716 linear again, making it easier for future maintainers to see what has
717 happened. Rebase as follows (assuming your work was on the branch
718 "committer/somework"):
719 % git checkout committer/somework
721 % git rebase blead
722 Then you can merge it into master like this:
724 % git checkout blead
726 % git merge --no-ff --no-commit committer/somework
727 % git commit -a
728 The switches above deserve explanation. "--no-ff" indicates that even
730 if all your work can be applied linearly against blead, a merge commit
731 should still be prepared. This ensures that all your work will be
732 shown as a side branch, with all its commits merged into the mainstream
733 blead by the merge commit.
734 "--no-commit" means that the merge commit will be prepared but not
736 committed. The commit is then actually performed when you run the next
737 command, which will bring up your editor to describe the commit.
738 Without "--no-commit", the commit would be made with nearly no useful
739 message, which would greatly diminish the value of the merge commit as
740 a placeholder for the work's description.
741 When describing the merge commit, explain the purpose of the branch,
743 and keep in mind that this description will probably be used by the
744 eventual release engineer when reviewing the next perldelta document.
745 If the subsequent push fails then you must be careful on how you
747 rebase. If you use
748 % git rebase p5p/blead
750 or
752 % git pull --rebase
754 then your carefully created merge commit will be lost! To avoid this
756 you can use:
757 % git fetch p5p
759 % git rebase --rebase-merges p5p/blead
760 This will recreate your merge commit.
762 (Should you be stuck with an older version of git (prior to 2.18), then
764 "git rebase" will not have the "--rebase-merges" switch, instead you
765 have to use the "--preserve-merges" switch.)
766 Committing to maintenance versions
768 Maintenance versions should only be altered to add critical bug fixes,
769 see perlpolicy.
770 To commit to a maintenance version of perl, you need to create a local
772 tracking branch:
773 % git checkout --track -b maint-5.005 origin/maint-5.005
775 This creates a local branch named "maint-5.005", which tracks the
777 remote branch "origin/maint-5.005". Then you can pull, commit, merge
778 and push as before.
779 You can also cherry-pick commits from blead and another branch, by
781 using the "git cherry-pick" command. It is recommended to use the -x
782 option to "git cherry-pick" in order to record the SHA1 of the original
783 commit in the new commit message.
784 Before pushing any change to a maint version, make sure you've
786 satisfied the steps in "Committing to blead" above.
787 Using a smoke-me branch to test changes
789 Sometimes a change affects code paths which you cannot test on the OSes
790 which are directly available to you and it would be wise to have users
791 on other OSes test the change before you commit it to blead.
792 Fortunately, there is a way to get your change smoke-tested on various
794 OSes: push it to a "smoke-me" branch and wait for certain automated
795 smoke-testers to report the results from their OSes. A "smoke-me"
796 branch is identified by the branch name: specifically, as seen on
797 github.com it must be a local branch whose first name component is
798 precisely "smoke-me".
799 The procedure for doing this is roughly as follows (using the example
801 of tonyc's smoke-me branch called win32stat):
802 First, make a local branch and switch to it:
804 % git checkout -b win32stat
806 Make some changes, build perl and test your changes, then commit them
808 to your local branch. Then push your local branch to a remote smoke-me
809 branch:
810 % git push origin win32stat:smoke-me/tonyc/win32stat
812 Now you can switch back to blead locally:
814 % git checkout blead
816 and continue working on other things while you wait a day or two,
818 keeping an eye on the results reported for your smoke-me branch at
819 <http://perl.develop-help.com/?b=smoke-me/tonyc/win32state>.
820 If all is well then update your blead branch:
822 % git pull
824 then checkout your smoke-me branch once more and rebase it on blead:
826 % git rebase blead win32stat
828 Now switch back to blead and merge your smoke-me branch into it:
830 % git checkout blead
832 % git merge win32stat
833 As described earlier, if there are many changes on your smoke-me branch
835 then you should prepare a merge commit in which to give an overview of
836 those changes by using the following command instead of the last
837 command above:
838 % git merge win32stat --no-ff --no-commit
840 You should now build perl and test your (merged) changes one last time
842 (ideally run the whole test suite, but failing that at least run the
843 t/porting/*.t tests) before pushing your changes as usual:
844 % git push origin blead
846 Finally, you should then delete the remote smoke-me branch:
848 % git push origin :smoke-me/tonyc/win32stat
850 (which is likely to produce a warning like this, which can be ignored:
852 remote: fatal: ambiguous argument
854 'refs/heads/smoke-me/tonyc/win32stat':
855 unknown revision or path not in the working tree.
856 remote: Use '--' to separate paths from revisions
857 ) and then delete your local branch:
859 % git branch -d win32stat
861perl v5.38.2 2023-11-30 PERLGIT(1)