3 perlrepository - Using the Perl source repository
7 All of Perl's source code is kept centrally in a Git repository. The
8 repository contains many Perl revisions from Perl 1 onwards and all the
9 revisions from Perforce, the version control system we were using
10 previously. This repository is accessible in different ways.
12 The full repository takes up about 80MB of disk space. A check out of
13 the blead branch (that is, the master branch, which contains bleadperl,
14 the development version of perl 5) takes up about 160MB of disk space
15 (including the repository). A build of bleadperl takes up about 200MB
16 (including the repository and the check out).
18 =head1 GETTING ACCESS TO THE REPOSITORY
20 =head2 READ ACCESS VIA THE WEB
22 You may access this over the web. This allows you to browse the tree,
23 see recent commits, search for particular commits and more. You may
26 http://perl5.git.perl.org/perl.git
28 =head2 READ ACCESS VIA GIT
30 You will need a copy of Git for your computer. You can fetch a copy of
31 the repository using the Git protocol (which uses port 9418):
33 git clone git://perl5.git.perl.org/perl.git perl-git
35 This clones the repository and makes a local copy in the 'perl-git'
38 If your local network does not allow you to use port 9418, then you can
39 fetch a copy of the repository over HTTP (this is slower):
41 git clone http://perl5.git.perl.org/perl.git perl-http
43 This clones the repository and makes a local copy in the 'perl-http'
46 =head2 WRITE ACCESS TO THE REPOSITORY
48 If you are a committer, then you can fetch a copy of the repository
49 that you can push back on with:
51 git clone ssh://perl5.git.perl.org/gitroot/perl.git perl-ssh
53 This clones the repository and makes a local copy in the 'perl-ssh'
56 If you clone using git, which is faster than ssh, then you will need to
57 modify your config in order to enable pushing. Edit F<.git/config>
58 where you will see something like:
61 url = git://perl5.git.perl.org/perl.git
63 change that to something like this:
66 url = ssh://perl5.git.perl.org/gitroot/perl.git
68 NOTE: there are symlinks set up so that the /gitroot is actually
71 You can also set up your user name and e-mail address. For example
73 % git config user.name "Leon Brocard"
74 % git config user.email acme@astray.com
76 It is also possible to keep C<origin> as a git remote, and add a new
77 remote for ssh access:
79 % git remote add camel user@camel:/gitroot/perl.git
81 This allows you to update your local repository by pulling from
82 C<origin>, which is faster and doesn't require you to authentify, and
83 to push your changes back with the C<camel> remote:
88 The C<fetch> command just updates the C<camel> refs, as the objects
89 themselves should have been fetched when pulling from C<origin>.
91 =head1 OVERVIEW OF THE REPOSITORY
93 Once you have changed into the repository directory, you can inspect
97 After a clone the repository will contain a single local branch, which
98 will be the current branch as well, as indicated by the asterix.
103 Using the -a switch to branch will also show the remote tracking
104 branches in the repository:
112 The branches that begin with "origin" correspond to the "git remote"
113 that you cloned from (which is named "origin"). Each branch on the
114 remote will be exactly tracked by theses branches. You should NEVER do
115 work on these remote tracking branches. You only ever do work in a
116 local branch. Local branches can be configured to automerge (on pull)
117 from a designated remote tracking branch. This is the case with the
118 default branch C<blead> which will be configured to merge from the
119 remote tracking branch C<origin/blead>.
121 You can see recent commits:
125 And pull new changes from the repository, and update your local
126 repository (must be clean first)
130 Assuming we are on the branch C<blead> immediately after a pull, this
131 command would be more or less equivalent to:
134 % git merge origin/blead
136 In fact if you want to update your local repository without touching
137 your working directory you do:
141 And if you want to update your remote-tracking branches for all defined
142 remotes simultaneously you can do
146 Neither of these last two commands will update your working directory,
147 however both will update the remote-tracking branches in your
150 To switch to another branch:
152 % git checkout origin/maint-5.8-dor
154 To make a local branch of a remote branch:
156 % git checkout -b maint-5.10 origin/maint-5.10
158 To switch back to blead:
162 =head2 FINDING OUT YOUR STATUS
164 The most common git command you will use will probably be
168 This command will produce as output a description of the current state
169 of the repository, including modified files and unignored untracked
170 files, and in addition it will show things like what files have been
171 staged for the next commit, and usually some useful information about
172 how to change things. For instance the following:
176 # Your branch is ahead of 'origin/blead' by 1 commit.
178 # Changes to be committed:
179 # (use "git reset HEAD <file>..." to unstage)
181 # modified: pod/perlrepository.pod
183 # Changed but not updated:
184 # (use "git add <file>..." to update what will be committed)
186 # modified: pod/perlrepository.pod
189 # (use "git add <file>..." to include in what will be committed)
191 # deliberate.untracked
193 This shows that there were changes to this document staged for commit,
194 and that there were further changes in the working directory not yet
195 staged. It also shows that there was an untracked file in the working
196 directory, and as you can see shows how to change all of this. It also
197 shows that there is one commit on the working branch C<blead> which
198 has not been pushed to the C<origin> remote yet. B<NOTE>: that this
199 output is also what you see as a template if you do not provide a
200 message to C<git commit>.
202 Assuming we commit all the mentioned changes above:
204 % git commit -a -m'explain git status and stuff about remotes'
205 Created commit daf8e63: explain git status and stuff about remotes
206 1 files changed, 83 insertions(+), 3 deletions(-)
208 We can re-run git status and see something like this:
212 # Your branch is ahead of 'origin/blead' by 2 commits.
215 # (use "git add <file>..." to include in what will be committed)
217 # deliberate.untracked
218 nothing added to commit but untracked files present (use "git add" to track)
221 When in doubt, before you do anything else, check your status and read
222 it carefully, many questions are answered directly by the git status
225 =head1 SUBMITTING A PATCH
227 If you have a patch in mind for Perl, you should first get a copy of
230 % git clone git://perl5.git.perl.org/perl.git perl-git
232 Then change into the directory:
236 Alternatively, if you already have a Perl repository, you should ensure
237 that you're on the I<blead> branch, and your repository is up to date:
242 Now that we have everything up to date, we need to create a temporary
243 new branch for these changes and switch into it:
245 % git checkout -b orange
247 which is the short form of
250 % git checkout orange
252 Then make your changes. For example, if Leon Brocard changes his name
253 to Orange Brocard, we should change his name in the AUTHORS file:
255 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
257 You can see what files are changed:
261 # Changes to be committed:
262 # (use "git reset HEAD <file>..." to unstage)
267 And you can see the changes:
270 diff --git a/AUTHORS b/AUTHORS
271 index 293dd70..722c93e 100644
274 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
275 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
276 Leif Huhn <leif@hale.dkstat.com>
277 Len Johnson <lenjay@ibm.net>
278 -Leon Brocard <acme@astray.com>
279 +Orange Brocard <acme@astray.com>
280 Les Peters <lpeters@aol.net>
281 Lesley Binks <lesley.binks@gmail.com>
282 Lincoln D. Stein <lstein@cshl.org>
284 Now commit your change locally:
287 % git commit -m 'Rename Leon Brocard to Orange Brocard'
288 Created commit 6196c1d: Rename Leon Brocard to Orange Brocard
289 1 files changed, 1 insertions(+), 1 deletions(-)
291 Now you should create a patch file for all your local changes:
293 % git format-patch origin
294 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
296 You should now send an email to perl5-porters@perl.org with a
297 description of your changes, and attach this patch file as an
300 If you want to delete your temporary branch, you may do so with:
303 % git branch -d orange
304 error: The branch 'orange' is not an ancestor of your current HEAD.
305 If you are sure you want to delete it, run 'git branch -D orange'.
306 % git branch -D orange
307 Deleted branch orange.
309 =head1 ACCEPTING A PATCH
311 If you have received a patch file generated using the above section,
312 you should try out the patch.
314 First we need to create a temporary new branch for these changes and
317 % git checkout -b experimental
319 Patches that were formatted by C<git format-patch> are applied with
322 % git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
323 Applying Rename Leon Brocard to Orange Brocard
325 If just a raw diff is provided, it is also possible use this two-step
328 % git apply bugfix.diff
329 % git commit -am "Some fixing" --author="That Guy <that.guy@internets.com>"
331 Now we can inspect the change:
334 commit b1b3dab48344cff6de4087efca3dbd63548ab5e2
335 Author: Leon Brocard <acme@astray.com>
336 Date: Fri Dec 19 17:02:59 2008 +0000
338 Rename Leon Brocard to Orange Brocard
342 diff --git a/AUTHORS b/AUTHORS
343 index 293dd70..722c93e 100644
346 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
347 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
348 Leif Huhn <leif@hale.dkstat.com>
349 Len Johnson <lenjay@ibm.net>
350 -Leon Brocard <acme@astray.com>
351 +Orange Brocard <acme@astray.com>
352 Les Peters <lpeters@aol.net>
353 Lesley Binks <lesley.binks@gmail.com>
354 Lincoln D. Stein <lstein@cshl.org>
356 If you are a committer to Perl and you think the patch is good, you can
357 then merge it into blead then push it out to the main repository:
360 % git merge experimental
363 If you want to delete your temporary branch, you may do so with:
366 % git branch -d experimental
367 error: The branch 'experimental' is not an ancestor of your current HEAD.
368 If you are sure you want to delete it, run 'git branch -D experimental'.
369 % git branch -D experimental
370 Deleted branch experimental.
372 =head1 CLEANING A WORKING DIRECTORY
374 The command C<git clean> can with varying arguments be used as a
375 replacement for make-clean.
377 To reset your working directory to a pristine condition you can do:
381 However, be aware this will delete ALL untracked content. You can use
385 to remove all ignored untracked files, such as build and test
386 byproduct, but leave any manually created files alone.
390 C<git> provides a built-in way to determine, with a binary search in
391 the history, which commit should be blamed for introducing a given bug.
393 Suppose that we have a script F<~/testcase.pl> that exits with C<0>
394 when some behaviour is correct, and with C<1> when it's faulty. We need
395 an helper script that automates building C<perl> and running the
401 # If you can use ccache, add -Dcc=ccache\ gcc -Dld=gcc to the Configure line
402 sh Configure -des -Dusedevel -Doptimize="-g" || exit 125
404 ./perl -Ilib ~/testcase.pl
406 This script may return C<125> to indicate that the corresponding commit
407 should be skipped. Otherwise, it returns the status of
410 We first enter in bisect mode with:
414 For example, if the bug is present on C<HEAD> but wasn't in 5.10.0,
415 C<git> will learn about this when you enter:
418 % git bisect good perl-5.10.0
419 Bisecting: 853 revisions left to test after this
421 This results in checking out the median commit between C<HEAD> and
422 C<perl-5.10.0>. We can then run the bisecting process with:
424 % git bisect run ~/run
426 When the first bad commit is isolated, C<git bisect> will tell you so:
428 ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit
429 commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5
430 Author: Dave Mitchell <davem@fdisolutions.com>
431 Date: Sat Feb 9 14:56:23 2008 +0000
433 [perl #49472] Attributes + Unkown Error
438 You can peek into the bisecting process with C<git bisect log> and
439 C<git bisect visualize>. C<git bisect reset> will get you out of bisect
442 Please note that the first C<good> state must be an ancestor of the
443 first C<bad> state. If you want to search for the commit that I<solved>
444 some bug, you have to negate your test case (i.e. exit with C<1> if OK
445 and C<0> if not) and still mark the lower bound as C<good> and the
446 upper as C<bad>. The "first bad commit" has then to be understood as
447 the "first commit where the bug is solved".
449 C<git help bisect> has much more information on how you can tweak your
452 =head1 COMITTING TO MAINTENANCE VERSIONS
454 To commit to a maintenance version of perl, you need to create a local
457 % git checkout --track -b maint-5.005 origin/maint-5.005
459 This creates a local branch named maint-5.005, which tracks the remote
460 branch origin/maint-5.005. Then you can pull, commit, merge and push as