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49781f4a AB |
1 | =encoding utf8 |
2 | ||
0549aefb LB |
3 | =for comment |
4 | Consistent formatting of this file is achieved with: | |
04c692a8 | 5 | perl ./Porting/podtidy pod/perlgit.pod |
0549aefb | 6 | |
d7dd28b6 LB |
7 | =head1 NAME |
8 | ||
04c692a8 | 9 | perlgit - Detailed information about git and the Perl repository |
d7dd28b6 | 10 | |
04c692a8 | 11 | =head1 DESCRIPTION |
d7dd28b6 | 12 | |
04c692a8 DR |
13 | This document provides details on using git to develop Perl. If you are |
14 | just interested in working on a quick patch, see L<perlhack> first. | |
15 | This document is intended for people who are regular contributors to | |
16 | Perl, including those with write access to the git repository. | |
184487f0 | 17 | |
04c692a8 | 18 | =head1 CLONING THE REPOSITORY |
f6c12373 | 19 | |
04c692a8 | 20 | All of Perl's source code is kept centrally in a Git repository at |
47ef154c | 21 | I<github.com>. |
f6c12373 | 22 | |
04c692a8 | 23 | You can make a read-only clone of the repository by running: |
f6c12373 | 24 | |
a85e04e2 | 25 | % git clone git@github.com:Perl/perl5.git perl |
f6c12373 | 26 | |
a85e04e2 | 27 | If you cannot use that for firewall reasons, you can also clone via http: |
3482f01a | 28 | |
47ef154c | 29 | % git clone https://github.com/Perl/perl5.git perl |
b47aa495 | 30 | |
04c692a8 | 31 | =head1 WORKING WITH THE REPOSITORY |
d7dd28b6 | 32 | |
6acba58e | 33 | Once you have changed into the repository directory, you can inspect |
04c692a8 DR |
34 | it. After a clone the repository will contain a single local branch, |
35 | which will be the current branch as well, as indicated by the asterisk. | |
39219fd3 YO |
36 | |
37 | % git branch | |
38 | * blead | |
39 | ||
f755e97d | 40 | Using the -a switch to C<branch> will also show the remote tracking |
6acba58e | 41 | branches in the repository: |
39219fd3 | 42 | |
d9847473 | 43 | % git branch -a |
09081495 | 44 | * blead |
d7dd28b6 LB |
45 | origin/HEAD |
46 | origin/blead | |
47 | ... | |
48 | ||
6acba58e LB |
49 | The branches that begin with "origin" correspond to the "git remote" |
50 | that you cloned from (which is named "origin"). Each branch on the | |
c9d1da35 | 51 | remote will be exactly tracked by these branches. You should NEVER do |
6acba58e LB |
52 | work on these remote tracking branches. You only ever do work in a |
53 | local branch. Local branches can be configured to automerge (on pull) | |
54 | from a designated remote tracking branch. This is the case with the | |
55 | default branch C<blead> which will be configured to merge from the | |
56 | remote tracking branch C<origin/blead>. | |
39219fd3 | 57 | |
d7dd28b6 LB |
58 | You can see recent commits: |
59 | ||
c2cf2042 | 60 | % git log |
d7dd28b6 | 61 | |
6acba58e LB |
62 | And pull new changes from the repository, and update your local |
63 | repository (must be clean first) | |
d7dd28b6 LB |
64 | |
65 | % git pull | |
09081495 | 66 | |
6acba58e LB |
67 | Assuming we are on the branch C<blead> immediately after a pull, this |
68 | command would be more or less equivalent to: | |
39219fd3 YO |
69 | |
70 | % git fetch | |
71 | % git merge origin/blead | |
72 | ||
6acba58e LB |
73 | In fact if you want to update your local repository without touching |
74 | your working directory you do: | |
39219fd3 YO |
75 | |
76 | % git fetch | |
77 | ||
6acba58e LB |
78 | And if you want to update your remote-tracking branches for all defined |
79 | remotes simultaneously you can do | |
39219fd3 YO |
80 | |
81 | % git remote update | |
82 | ||
6acba58e LB |
83 | Neither of these last two commands will update your working directory, |
84 | however both will update the remote-tracking branches in your | |
85 | repository. | |
39219fd3 | 86 | |
6051489b NC |
87 | To make a local branch of a remote branch: |
88 | ||
89 | % git checkout -b maint-5.10 origin/maint-5.10 | |
90 | ||
09081495 LB |
91 | To switch back to blead: |
92 | ||
93 | % git checkout blead | |
c2cf2042 | 94 | |
ba336be1 | 95 | =head2 Finding out your status |
39219fd3 YO |
96 | |
97 | The most common git command you will use will probably be | |
98 | ||
99 | % git status | |
100 | ||
6acba58e LB |
101 | This command will produce as output a description of the current state |
102 | of the repository, including modified files and unignored untracked | |
103 | files, and in addition it will show things like what files have been | |
104 | staged for the next commit, and usually some useful information about | |
105 | how to change things. For instance the following: | |
39219fd3 | 106 | |
c7956846 KW |
107 | % git status |
108 | On branch blead | |
109 | Your branch is ahead of 'origin/blead' by 1 commit. | |
82217626 | 110 | |
c7956846 KW |
111 | Changes to be committed: |
112 | (use "git reset HEAD <file>..." to unstage) | |
82217626 | 113 | |
c7956846 | 114 | modified: pod/perlgit.pod |
82217626 | 115 | |
c7956846 KW |
116 | Changes not staged for commit: |
117 | (use "git add <file>..." to update what will be committed) | |
118 | (use "git checkout -- <file>..." to discard changes in working | |
119 | directory) | |
82217626 | 120 | |
c7956846 | 121 | modified: pod/perlgit.pod |
82217626 | 122 | |
c7956846 KW |
123 | Untracked files: |
124 | (use "git add <file>..." to include in what will be committed) | |
82217626 | 125 | |
c7956846 | 126 | deliberate.untracked |
39219fd3 | 127 | |
6acba58e LB |
128 | This shows that there were changes to this document staged for commit, |
129 | and that there were further changes in the working directory not yet | |
130 | staged. It also shows that there was an untracked file in the working | |
131 | directory, and as you can see shows how to change all of this. It also | |
0549aefb | 132 | shows that there is one commit on the working branch C<blead> which has |
ff28a605 | 133 | not been pushed to the C<origin> remote yet. B<NOTE>: This output |
0549aefb LB |
134 | is also what you see as a template if you do not provide a message to |
135 | C<git commit>. | |
7f6effc7 | 136 | |
04c692a8 | 137 | =head2 Patch workflow |
7f6effc7 | 138 | |
04c692a8 DR |
139 | First, please read L<perlhack> for details on hacking the Perl core. |
140 | That document covers many details on how to create a good patch. | |
7f6effc7 | 141 | |
04c692a8 DR |
142 | If you already have a Perl repository, you should ensure that you're on |
143 | the I<blead> branch, and your repository is up to date: | |
12322d22 A |
144 | |
145 | % git checkout blead | |
146 | % git pull | |
147 | ||
6a7cbfe8 LB |
148 | It's preferable to patch against the latest blead version, since this |
149 | is where new development occurs for all changes other than critical bug | |
04c692a8 | 150 | fixes. Critical bug fix patches should be made against the relevant |
7f4ffa9d RS |
151 | maint branches, or should be submitted with a note indicating all the |
152 | branches where the fix should be applied. | |
a44f43ac | 153 | |
6acba58e LB |
154 | Now that we have everything up to date, we need to create a temporary |
155 | new branch for these changes and switch into it: | |
b1fccde5 | 156 | |
a9b05323 | 157 | % git checkout -b orange |
23f8d33e | 158 | |
a9b05323 YO |
159 | which is the short form of |
160 | ||
b1fccde5 LB |
161 | % git branch orange |
162 | % git checkout orange | |
163 | ||
0c24b290 AB |
164 | Creating a topic branch makes it easier for the maintainers to rebase |
165 | or merge back into the master blead for a more linear history. If you | |
77db6475 LB |
166 | don't work on a topic branch the maintainer has to manually cherry pick |
167 | your changes onto blead before they can be applied. | |
0c24b290 | 168 | |
77db6475 | 169 | That'll get you scolded on perl5-porters, so don't do that. Be Awesome. |
0c24b290 | 170 | |
c2cf2042 LB |
171 | Then make your changes. For example, if Leon Brocard changes his name |
172 | to Orange Brocard, we should change his name in the AUTHORS file: | |
173 | ||
174 | % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS | |
175 | ||
176 | You can see what files are changed: | |
177 | ||
178 | % git status | |
82217626 LM |
179 | On branch orange |
180 | Changes to be committed: | |
181 | (use "git reset HEAD <file>..." to unstage) | |
182 | ||
183 | modified: AUTHORS | |
c2cf2042 | 184 | |
c2cf2042 LB |
185 | And you can see the changes: |
186 | ||
c7956846 KW |
187 | % git diff |
188 | diff --git a/AUTHORS b/AUTHORS | |
189 | index 293dd70..722c93e 100644 | |
190 | --- a/AUTHORS | |
191 | +++ b/AUTHORS | |
192 | @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie> | |
193 | Laszlo Molnar <laszlo.molnar@eth.ericsson.se> | |
194 | Leif Huhn <leif@hale.dkstat.com> | |
195 | Len Johnson <lenjay@ibm.net> | |
196 | -Leon Brocard <acme@astray.com> | |
197 | +Orange Brocard <acme@astray.com> | |
198 | Les Peters <lpeters@aol.net> | |
199 | Lesley Binks <lesley.binks@gmail.com> | |
200 | Lincoln D. Stein <lstein@cshl.org> | |
c2cf2042 | 201 | |
04c692a8 | 202 | Now commit your change locally: |
77471e41 | 203 | |
c7956846 KW |
204 | % git commit -a -m 'Rename Leon Brocard to Orange Brocard' |
205 | Created commit 6196c1d: Rename Leon Brocard to Orange Brocard | |
206 | 1 files changed, 1 insertions(+), 1 deletions(-) | |
77471e41 | 207 | |
04c692a8 DR |
208 | The C<-a> option is used to include all files that git tracks that you |
209 | have changed. If at this time, you only want to commit some of the | |
210 | files you have worked on, you can omit the C<-a> and use the command | |
211 | C<S<git add I<FILE ...>>> before doing the commit. C<S<git add | |
212 | --interactive>> allows you to even just commit portions of files | |
213 | instead of all the changes in them. | |
77471e41 | 214 | |
04c692a8 DR |
215 | The C<-m> option is used to specify the commit message. If you omit it, |
216 | git will open a text editor for you to compose the message | |
217 | interactively. This is useful when the changes are more complex than | |
218 | the sample given here, and, depending on the editor, to know that the | |
219 | first line of the commit message doesn't exceed the 50 character legal | |
47ef154c DB |
220 | maximum. See L<perlhack/Commit message> for more information about what |
221 | makes a good commit message. | |
77471e41 | 222 | |
04c692a8 DR |
223 | Once you've finished writing your commit message and exited your |
224 | editor, git will write your change to disk and tell you something like | |
225 | this: | |
77471e41 | 226 | |
c7956846 KW |
227 | Created commit daf8e63: explain git status and stuff about remotes |
228 | 1 files changed, 83 insertions(+), 3 deletions(-) | |
c2cf2042 | 229 | |
04c692a8 | 230 | If you re-run C<git status>, you should see something like this: |
c2cf2042 | 231 | |
c7956846 KW |
232 | % git status |
233 | On branch orange | |
234 | Untracked files: | |
235 | (use "git add <file>..." to include in what will be committed) | |
82217626 | 236 | |
c7956846 | 237 | deliberate.untracked |
82217626 | 238 | |
c7956846 KW |
239 | nothing added to commit but untracked files present (use "git add" to |
240 | track) | |
2be70973 | 241 | |
04c692a8 DR |
242 | When in doubt, before you do anything else, check your status and read |
243 | it carefully, many questions are answered directly by the git status | |
244 | output. | |
2be70973 | 245 | |
dc3c3040 GA |
246 | You can examine your last commit with: |
247 | ||
248 | % git show HEAD | |
249 | ||
250 | and if you are not happy with either the description or the patch | |
c26da522 | 251 | itself you can fix it up by editing the files once more and then issue: |
dc3c3040 GA |
252 | |
253 | % git commit -a --amend | |
254 | ||
617d9ec4 DB |
255 | Now, create a fork on GitHub to push your branch to, and add it as a |
256 | remote if you haven't already, as described in the GitHub documentation | |
257 | at L<https://help.github.com/en/articles/working-with-forks>: | |
c2cf2042 | 258 | |
617d9ec4 | 259 | % git remote add fork git@github.com:MyUser/perl5.git |
c2cf2042 | 260 | |
617d9ec4 | 261 | And push the branch to your fork: |
9420b3b3 | 262 | |
617d9ec4 | 263 | % git push -u fork orange |
9420b3b3 | 264 | |
617d9ec4 DB |
265 | You should now submit a Pull Request (PR) on GitHub from the new branch |
266 | to blead. For more information, see the GitHub documentation at | |
267 | L<https://help.github.com/en/articles/creating-a-pull-request-from-a-fork>. | |
268 | ||
269 | You can also send patch files to | |
04c692a8 DR |
270 | L<perl5-porters@perl.org|mailto:perl5-porters@perl.org> directly if the |
271 | patch is not ready to be applied, but intended for discussion. | |
64a8e22b | 272 | |
617d9ec4 DB |
273 | To create a patch file for all your local changes: |
274 | ||
275 | % git format-patch -M blead.. | |
276 | 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch | |
277 | ||
278 | Or for a lot of changes, e.g. from a topic branch: | |
279 | ||
280 | % git format-patch --stdout -M blead.. > topic-branch-changes.patch | |
c2cf2042 | 281 | |
b1fccde5 LB |
282 | If you want to delete your temporary branch, you may do so with: |
283 | ||
c7956846 KW |
284 | % git checkout blead |
285 | % git branch -d orange | |
286 | error: The branch 'orange' is not an ancestor of your current HEAD. | |
287 | If you are sure you want to delete it, run 'git branch -D orange'. | |
288 | % git branch -D orange | |
289 | Deleted branch orange. | |
7df2e4bc | 290 | |
a44f43ac RGS |
291 | =head2 A note on derived files |
292 | ||
293 | Be aware that many files in the distribution are derivative--avoid | |
0549aefb | 294 | patching them, because git won't see the changes to them, and the build |
04c692a8 | 295 | process will overwrite them. Patch the originals instead. Most |
0549aefb | 296 | utilities (like perldoc) are in this category, i.e. patch |
77db6475 | 297 | F<utils/perldoc.PL> rather than F<utils/perldoc>. Similarly, don't |
11fa7e22 LM |
298 | create patches for files under F<$src_root/ext> from their copies found |
299 | in F<$install_root/lib>. If you are unsure about the proper location of | |
300 | a file that may have gotten copied while building the source | |
301 | distribution, consult the F<MANIFEST>. | |
a44f43ac | 302 | |
04c692a8 | 303 | =head2 Cleaning a working directory |
b0d36535 | 304 | |
6acba58e | 305 | The command C<git clean> can with varying arguments be used as a |
dc3c3040 | 306 | replacement for C<make clean>. |
b0d36535 YO |
307 | |
308 | To reset your working directory to a pristine condition you can do: | |
309 | ||
e0b2b458 | 310 | % git clean -dxf |
b0d36535 YO |
311 | |
312 | However, be aware this will delete ALL untracked content. You can use | |
313 | ||
e0b2b458 | 314 | % git clean -Xf |
b0d36535 | 315 | |
6acba58e | 316 | to remove all ignored untracked files, such as build and test |
11fa7e22 | 317 | byproduct, but leave any manually created files alone. |
b0d36535 | 318 | |
0549aefb | 319 | If you only want to cancel some uncommitted edits, you can use C<git |
c26da522 LB |
320 | checkout> and give it a list of files to be reverted, or C<git checkout |
321 | -f> to revert them all. | |
f755e97d RGS |
322 | |
323 | If you want to cancel one or several commits, you can use C<git reset>. | |
324 | ||
04c692a8 | 325 | =head2 Bisecting |
d82a90c1 | 326 | |
5b9539f4 NC |
327 | C<git> provides a built-in way to determine which commit should be blamed |
328 | for introducing a given bug. C<git bisect> performs a binary search of | |
329 | history to locate the first failing commit. It is fast, powerful and | |
330 | flexible, but requires some setup and to automate the process an auxiliary | |
331 | shell script is needed. | |
332 | ||
333 | The core provides a wrapper program, F<Porting/bisect.pl>, which attempts to | |
334 | simplify as much as possible, making bisecting as simple as running a Perl | |
335 | one-liner. For example, if you want to know when this became an error: | |
336 | ||
337 | perl -e 'my $a := 2' | |
338 | ||
339 | you simply run this: | |
340 | ||
341 | .../Porting/bisect.pl -e 'my $a := 2;' | |
342 | ||
11fa7e22 LM |
343 | Using F<Porting/bisect.pl>, with one command (and no other files) it's easy to |
344 | find out | |
5b9539f4 NC |
345 | |
346 | =over 4 | |
347 | ||
348 | =item * | |
349 | ||
350 | Which commit caused this example code to break? | |
351 | ||
352 | =item * | |
353 | ||
354 | Which commit caused this example code to start working? | |
355 | ||
356 | =item * | |
357 | ||
358 | Which commit added the first file to match this regex? | |
359 | ||
360 | =item * | |
361 | ||
362 | Which commit removed the last file to match this regex? | |
363 | ||
364 | =back | |
365 | ||
366 | usually without needing to know which versions of perl to use as start and | |
11fa7e22 LM |
367 | end revisions, as F<Porting/bisect.pl> automatically searches to find the |
368 | earliest stable version for which the test case passes. Run | |
5b9539f4 NC |
369 | C<Porting/bisect.pl --help> for the full documentation, including how to |
370 | set the C<Configure> and build time options. | |
371 | ||
372 | If you require more flexibility than F<Porting/bisect.pl> has to offer, you'll | |
373 | need to run C<git bisect> yourself. It's most useful to use C<git bisect run> | |
374 | to automate the building and testing of perl revisions. For this you'll need | |
375 | a shell script for C<git> to call to test a particular revision. An example | |
376 | script is F<Porting/bisect-example.sh>, which you should copy B<outside> of | |
377 | the repository, as the bisect process will reset the state to a clean checkout | |
378 | as it runs. The instructions below assume that you copied it as F<~/run> and | |
379 | then edited it as appropriate. | |
d82a90c1 | 380 | |
bdaf0bc6 | 381 | You first enter in bisect mode with: |
d82a90c1 VP |
382 | |
383 | % git bisect start | |
384 | ||
6acba58e LB |
385 | For example, if the bug is present on C<HEAD> but wasn't in 5.10.0, |
386 | C<git> will learn about this when you enter: | |
d82a90c1 VP |
387 | |
388 | % git bisect bad | |
389 | % git bisect good perl-5.10.0 | |
390 | Bisecting: 853 revisions left to test after this | |
391 | ||
6acba58e | 392 | This results in checking out the median commit between C<HEAD> and |
bdaf0bc6 | 393 | C<perl-5.10.0>. You can then run the bisecting process with: |
d82a90c1 VP |
394 | |
395 | % git bisect run ~/run | |
396 | ||
397 | When the first bad commit is isolated, C<git bisect> will tell you so: | |
398 | ||
399 | ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit | |
400 | commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 | |
401 | Author: Dave Mitchell <davem@fdisolutions.com> | |
402 | Date: Sat Feb 9 14:56:23 2008 +0000 | |
403 | ||
9469eb4a | 404 | [perl #49472] Attributes + Unknown Error |
d82a90c1 VP |
405 | ... |
406 | ||
407 | bisect run success | |
408 | ||
6acba58e LB |
409 | You can peek into the bisecting process with C<git bisect log> and |
410 | C<git bisect visualize>. C<git bisect reset> will get you out of bisect | |
411 | mode. | |
d82a90c1 | 412 | |
6acba58e LB |
413 | Please note that the first C<good> state must be an ancestor of the |
414 | first C<bad> state. If you want to search for the commit that I<solved> | |
415 | some bug, you have to negate your test case (i.e. exit with C<1> if OK | |
416 | and C<0> if not) and still mark the lower bound as C<good> and the | |
417 | upper as C<bad>. The "first bad commit" has then to be understood as | |
418 | the "first commit where the bug is solved". | |
d82a90c1 | 419 | |
6acba58e LB |
420 | C<git help bisect> has much more information on how you can tweak your |
421 | binary searches. | |
feb5e972 | 422 | |
ca31f56c JK |
423 | Following bisection you may wish to configure, build and test perl at |
424 | commits identified by the bisection process. Sometimes, particularly | |
425 | with older perls, C<make> may fail during this process. In this case | |
426 | you may be able to patch the source code at the older commit point. To | |
427 | do so, please follow the suggestions provided in | |
428 | L<perlhack/Building perl at older commits>. | |
429 | ||
99cd8e46 | 430 | =head2 Topic branches and rewriting history |
9d68b7ed | 431 | |
04c692a8 | 432 | Individual committers should create topic branches under |
04edae75 | 433 | B<yourname>/B<some_descriptive_name>: |
03050721 | 434 | |
ff28a605 LM |
435 | % branch="$yourname/$some_descriptive_name" |
436 | % git checkout -b $branch | |
04edae75 | 437 | ... do local edits, commits etc ... |
ff28a605 | 438 | % git push origin -u $branch |
03050721 | 439 | |
04edae75 AP |
440 | Should you be stuck with an ancient version of git (prior to 1.7), then |
441 | C<git push> will not have the C<-u> switch, and you have to replace the | |
442 | last step with the following sequence: | |
443 | ||
ff28a605 LM |
444 | % git push origin $branch:refs/heads/$branch |
445 | % git config branch.$branch.remote origin | |
446 | % git config branch.$branch.merge refs/heads/$branch | |
04edae75 AP |
447 | |
448 | If you want to make changes to someone else's topic branch, you should | |
449 | check with its creator before making any change to it. | |
450 | ||
451 | You | |
04c692a8 DR |
452 | might sometimes find that the original author has edited the branch's |
453 | history. There are lots of good reasons for this. Sometimes, an author | |
454 | might simply be rebasing the branch onto a newer source point. | |
455 | Sometimes, an author might have found an error in an early commit which | |
456 | they wanted to fix before merging the branch to blead. | |
c26da522 | 457 | |
04c692a8 DR |
458 | Currently the master repository is configured to forbid |
459 | non-fast-forward merges. This means that the branches within can not be | |
460 | rebased and pushed as a single step. | |
c26da522 | 461 | |
04c692a8 DR |
462 | The only way you will ever be allowed to rebase or modify the history |
463 | of a pushed branch is to delete it and push it as a new branch under | |
464 | the same name. Please think carefully about doing this. It may be | |
465 | better to sequentially rename your branches so that it is easier for | |
466 | others working with you to cherry-pick their local changes onto the new | |
467 | version. (XXX: needs explanation). | |
c26da522 | 468 | |
04c692a8 DR |
469 | If you want to rebase a personal topic branch, you will have to delete |
470 | your existing topic branch and push as a new version of it. You can do | |
471 | this via the following formula (see the explanation about C<refspec>'s | |
472 | in the git push documentation for details) after you have rebased your | |
473 | branch: | |
c26da522 | 474 | |
cc116ce7 | 475 | # first rebase |
ff28a605 LM |
476 | % git checkout $user/$topic |
477 | % git fetch | |
478 | % git rebase origin/blead | |
c26da522 | 479 | |
cc116ce7 | 480 | # then "delete-and-push" |
ff28a605 LM |
481 | % git push origin :$user/$topic |
482 | % git push origin $user/$topic | |
c26da522 | 483 | |
04c692a8 DR |
484 | B<NOTE:> it is forbidden at the repository level to delete any of the |
485 | "primary" branches. That is any branch matching | |
486 | C<m!^(blead|maint|perl)!>. Any attempt to do so will result in git | |
487 | producing an error like this: | |
c26da522 | 488 | |
ff28a605 | 489 | % git push origin :blead |
cc116ce7 AP |
490 | *** It is forbidden to delete blead/maint branches in this repository |
491 | error: hooks/update exited with error code 1 | |
492 | error: hook declined to update refs/heads/blead | |
493 | To ssh://perl5.git.perl.org/perl | |
494 | ! [remote rejected] blead (hook declined) | |
495 | error: failed to push some refs to 'ssh://perl5.git.perl.org/perl' | |
c26da522 | 496 | |
04c692a8 DR |
497 | As a matter of policy we do B<not> edit the history of the blead and |
498 | maint-* branches. If a typo (or worse) sneaks into a commit to blead or | |
499 | maint-*, we'll fix it in another commit. The only types of updates | |
e7f1d4a7 | 500 | allowed on these branches are "fast-forwards", where all history is |
04c692a8 | 501 | preserved. |
2bab0636 | 502 | |
04c692a8 DR |
503 | Annotated tags in the canonical perl.git repository will never be |
504 | deleted or modified. Think long and hard about whether you want to push | |
e7f1d4a7 | 505 | a local tag to perl.git before doing so. (Pushing simple tags is |
04c692a8 | 506 | not allowed.) |
2bab0636 | 507 | |
feb5e972 | 508 | =head2 Grafts |
c26da522 | 509 | |
04c692a8 DR |
510 | The perl history contains one mistake which was not caught in the |
511 | conversion: a merge was recorded in the history between blead and | |
512 | maint-5.10 where no merge actually occurred. Due to the nature of git, | |
513 | this is now impossible to fix in the public repository. You can remove | |
514 | this mis-merge locally by adding the following line to your | |
515 | C<.git/info/grafts> file: | |
c26da522 | 516 | |
c7956846 | 517 | 296f12bbbbaa06de9be9d09d3dcf8f4528898a49 434946e0cb7a32589ed92d18008aaa1d88515930 |
c26da522 | 518 | |
04c692a8 DR |
519 | It is particularly important to have this graft line if any bisecting |
520 | is done in the area of the "merge" in question. | |
ce2a8773 | 521 | |
04c692a8 DR |
522 | =head1 WRITE ACCESS TO THE GIT REPOSITORY |
523 | ||
524 | Once you have write access, you will need to modify the URL for the | |
525 | origin remote to enable pushing. Edit F<.git/config> with the | |
526 | git-config(1) command: | |
527 | ||
47ef154c | 528 | % git config remote.origin.url git@github.com:Perl/perl5.git |
04c692a8 DR |
529 | |
530 | You can also set up your user name and e-mail address. Most people do | |
531 | this once globally in their F<~/.gitconfig> by doing something like: | |
532 | ||
533 | % git config --global user.name "Ævar Arnfjörð Bjarmason" | |
534 | % git config --global user.email avarab@gmail.com | |
535 | ||
ff28a605 | 536 | However, if you'd like to override that just for perl, |
04c692a8 DR |
537 | execute something like the following in F<perl>: |
538 | ||
539 | % git config user.email avar@cpan.org | |
540 | ||
541 | It is also possible to keep C<origin> as a git remote, and add a new | |
542 | remote for ssh access: | |
543 | ||
47ef154c | 544 | % git remote add camel git@github.com:Perl/perl5.git |
04c692a8 DR |
545 | |
546 | This allows you to update your local repository by pulling from | |
547 | C<origin>, which is faster and doesn't require you to authenticate, and | |
548 | to push your changes back with the C<camel> remote: | |
549 | ||
550 | % git fetch camel | |
551 | % git push camel | |
552 | ||
553 | The C<fetch> command just updates the C<camel> refs, as the objects | |
554 | themselves should have been fetched when pulling from C<origin>. | |
04baf1ff | 555 | |
6be38225 TC |
556 | =head2 Working with Github pull requests |
557 | ||
558 | Pull requests typically originate from outside of the C<Perl/perl.git> | |
559 | repository, so if you want to test or work with it locally a vanilla | |
560 | C<git fetch> from the C<Perl/perl5.git> repository won't fetch it. | |
561 | ||
562 | However Github does provide a mechanism to fetch a pull request to a | |
563 | local branch. They are available on Github remotes under C<pull/>, so | |
564 | you can use C<< git fetch pull/I<PRID>/head:I<localname> >> to make a | |
565 | local copy. eg. to fetch pull request 9999 to the local branch | |
566 | C<local-branch-name> run: | |
567 | ||
568 | git fetch origin pull/9999/head:local-branch-name | |
569 | ||
570 | and then: | |
571 | ||
572 | git checkout local-branch-name | |
573 | ||
574 | Note: this branch is not rebased on C<blead>, so instead of the | |
575 | checkout above, you might want: | |
576 | ||
577 | git rebase origin/blead local-branch-name | |
578 | ||
579 | which rebases C<local-branch-name> on C<blead>, and checks it out. | |
580 | ||
f7349d1a TC |
581 | Alternatively you can configure the remote to fetch all pull requests |
582 | as remote-tracking branches. To do this edit the remote in | |
583 | F<.git/config>, for example if your github remote is C<origin> you'd | |
584 | have: | |
585 | ||
586 | [remote "origin"] | |
587 | url = git@github.com:/Perl/perl5.git | |
588 | fetch = +refs/heads/*:refs/remotes/origin/* | |
589 | ||
590 | Add a line to map the remote pull request branches to remote-tracking | |
591 | branches: | |
592 | ||
593 | [remote "origin"] | |
594 | url = git@github.com:/Perl/perl5.git | |
595 | fetch = +refs/heads/*:refs/remotes/origin/* | |
596 | fetch = +refs/pull/*/head:refs/remotes/origin/pull/* | |
597 | ||
598 | and then do a fetch as normal: | |
599 | ||
600 | git fetch origin | |
601 | ||
602 | This will create a remote-tracking branch for every pull request, including | |
603 | closed requests. | |
604 | ||
605 | To remove those remote-tracking branches, remove the line added above | |
606 | and prune: | |
607 | ||
608 | git fetch -p origin # or git remote prune origin | |
609 | ||
99cd8e46 | 610 | =head2 Accepting a patch |
04c692a8 DR |
611 | |
612 | If you have received a patch file generated using the above section, | |
613 | you should try out the patch. | |
614 | ||
615 | First we need to create a temporary new branch for these changes and | |
616 | switch into it: | |
617 | ||
c7956846 | 618 | % git checkout -b experimental |
04c692a8 DR |
619 | |
620 | Patches that were formatted by C<git format-patch> are applied with | |
621 | C<git am>: | |
622 | ||
c7956846 KW |
623 | % git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch |
624 | Applying Rename Leon Brocard to Orange Brocard | |
04c692a8 | 625 | |
6fc2106e DM |
626 | Note that some UNIX mail systems can mess with text attachments containing |
627 | 'From '. This will fix them up: | |
628 | ||
c7956846 KW |
629 | % perl -pi -e's/^>From /From /' \ |
630 | 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch | |
6fc2106e | 631 | |
04c692a8 DR |
632 | If just a raw diff is provided, it is also possible use this two-step |
633 | process: | |
634 | ||
11fa7e22 | 635 | % git apply bugfix.diff |
a98780ae KW |
636 | % git commit -a -m "Some fixing" \ |
637 | --author="That Guy <that.guy@internets.com>" | |
edcf105d | 638 | |
04c692a8 DR |
639 | Now we can inspect the change: |
640 | ||
c7956846 KW |
641 | % git show HEAD |
642 | commit b1b3dab48344cff6de4087efca3dbd63548ab5e2 | |
643 | Author: Leon Brocard <acme@astray.com> | |
644 | Date: Fri Dec 19 17:02:59 2008 +0000 | |
645 | ||
646 | Rename Leon Brocard to Orange Brocard | |
647 | ||
648 | diff --git a/AUTHORS b/AUTHORS | |
649 | index 293dd70..722c93e 100644 | |
650 | --- a/AUTHORS | |
651 | +++ b/AUTHORS | |
652 | @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie> | |
653 | Laszlo Molnar <laszlo.molnar@eth.ericsson.se> | |
654 | Leif Huhn <leif@hale.dkstat.com> | |
655 | Len Johnson <lenjay@ibm.net> | |
656 | -Leon Brocard <acme@astray.com> | |
657 | +Orange Brocard <acme@astray.com> | |
658 | Les Peters <lpeters@aol.net> | |
659 | Lesley Binks <lesley.binks@gmail.com> | |
660 | Lincoln D. Stein <lstein@cshl.org> | |
04c692a8 DR |
661 | |
662 | If you are a committer to Perl and you think the patch is good, you can | |
663 | then merge it into blead then push it out to the main repository: | |
664 | ||
665 | % git checkout blead | |
666 | % git merge experimental | |
68382b67 | 667 | % git push origin blead |
04c692a8 DR |
668 | |
669 | If you want to delete your temporary branch, you may do so with: | |
670 | ||
c7956846 KW |
671 | % git checkout blead |
672 | % git branch -d experimental | |
673 | error: The branch 'experimental' is not an ancestor of your current | |
674 | HEAD. If you are sure you want to delete it, run 'git branch -D | |
675 | experimental'. | |
676 | % git branch -D experimental | |
677 | Deleted branch experimental. | |
04c692a8 DR |
678 | |
679 | =head2 Committing to blead | |
680 | ||
681 | The 'blead' branch will become the next production release of Perl. | |
edcf105d JV |
682 | |
683 | Before pushing I<any> local change to blead, it's incredibly important | |
684 | that you do a few things, lest other committers come after you with | |
685 | pitchforks and torches: | |
686 | ||
687 | =over | |
688 | ||
689 | =item * | |
690 | ||
04c692a8 DR |
691 | Make sure you have a good commit message. See L<perlhack/Commit |
692 | message> for details. | |
edcf105d JV |
693 | |
694 | =item * | |
695 | ||
04c692a8 DR |
696 | Run the test suite. You might not think that one typo fix would break a |
697 | test file. You'd be wrong. Here's an example of where not running the | |
698 | suite caused problems. A patch was submitted that added a couple of | |
11fa7e22 LM |
699 | tests to an existing F<.t>. It couldn't possibly affect anything else, so |
700 | no need to test beyond the single affected F<.t>, right? But, the | |
f76a37ee | 701 | submitter's email address had changed since the last of their |
04c692a8 | 702 | submissions, and this caused other tests to fail. Running the test |
f76a37ee | 703 | target given in the next item would have caught this problem. |
edcf105d JV |
704 | |
705 | =item * | |
706 | ||
707 | If you don't run the full test suite, at least C<make test_porting>. | |
708 | This will run basic sanity checks. To see which sanity checks, have a | |
709 | look in F<t/porting>. | |
710 | ||
cd78e84f CB |
711 | =item * |
712 | ||
713 | If you make any changes that affect miniperl or core routines that have | |
04baf1ff | 714 | different code paths for miniperl, be sure to run C<make minitest>. |
cd78e84f CB |
715 | This will catch problems that even the full test suite will not catch |
716 | because it runs a subset of tests under miniperl rather than perl. | |
717 | ||
edcf105d JV |
718 | =back |
719 | ||
99cd8e46 | 720 | =head2 On merging and rebasing |
961bfa8c RS |
721 | |
722 | Simple, one-off commits pushed to the 'blead' branch should be simple | |
723 | commits that apply cleanly. In other words, you should make sure your | |
724 | work is committed against the current position of blead, so that you can | |
725 | push back to the master repository without merging. | |
726 | ||
727 | Sometimes, blead will move while you're building or testing your | |
728 | changes. When this happens, your push will be rejected with a message | |
729 | like this: | |
730 | ||
c7956846 KW |
731 | To ssh://perl5.git.perl.org/perl.git |
732 | ! [rejected] blead -> blead (non-fast-forward) | |
733 | error: failed to push some refs to 'ssh://perl5.git.perl.org/perl.git' | |
734 | To prevent you from losing history, non-fast-forward updates were | |
735 | rejected Merge the remote changes (e.g. 'git pull') before pushing | |
736 | again. See the 'Note about fast-forwards' section of 'git push --help' | |
737 | for details. | |
961bfa8c RS |
738 | |
739 | When this happens, you can just I<rebase> your work against the new | |
740 | position of blead, like this (assuming your remote for the master | |
741 | repository is "p5p"): | |
742 | ||
ff28a605 LM |
743 | % git fetch p5p |
744 | % git rebase p5p/blead | |
961bfa8c RS |
745 | |
746 | You will see your commits being re-applied, and you will then be able to | |
c9d1da35 | 747 | push safely. More information about rebasing can be found in the |
961bfa8c RS |
748 | documentation for the git-rebase(1) command. |
749 | ||
750 | For larger sets of commits that only make sense together, or that would | |
751 | benefit from a summary of the set's purpose, you should use a merge | |
752 | commit. You should perform your work on a L<topic branch|/Topic | |
753 | branches and rewriting history>, which you should regularly rebase | |
754 | against blead to ensure that your code is not broken by blead moving. | |
bd3355a0 FC |
755 | When you have finished your work, please perform a final rebase and |
756 | test. Linear history is something that gets lost with every | |
757 | commit on blead, but a final rebase makes the history linear | |
758 | again, making it easier for future maintainers to see what has | |
759 | happened. Rebase as follows (assuming your work was on the | |
688cbe00 | 760 | branch C<< committer/somework >>): |
961bfa8c | 761 | |
ff28a605 LM |
762 | % git checkout committer/somework |
763 | % git rebase blead | |
bd3355a0 FC |
764 | |
765 | Then you can merge it into master like this: | |
766 | ||
ff28a605 LM |
767 | % git checkout blead |
768 | % git merge --no-ff --no-commit committer/somework | |
769 | % git commit -a | |
961bfa8c RS |
770 | |
771 | The switches above deserve explanation. C<--no-ff> indicates that even | |
772 | if all your work can be applied linearly against blead, a merge commit | |
773 | should still be prepared. This ensures that all your work will be shown | |
774 | as a side branch, with all its commits merged into the mainstream blead | |
775 | by the merge commit. | |
776 | ||
777 | C<--no-commit> means that the merge commit will be I<prepared> but not | |
778 | I<committed>. The commit is then actually performed when you run the | |
779 | next command, which will bring up your editor to describe the commit. | |
780 | Without C<--no-commit>, the commit would be made with nearly no useful | |
781 | message, which would greatly diminish the value of the merge commit as a | |
782 | placeholder for the work's description. | |
783 | ||
784 | When describing the merge commit, explain the purpose of the branch, and | |
785 | keep in mind that this description will probably be used by the | |
786 | eventual release engineer when reviewing the next perldelta document. | |
787 | ||
04c692a8 | 788 | =head2 Committing to maintenance versions |
9d68b7ed | 789 | |
77db6475 LB |
790 | Maintenance versions should only be altered to add critical bug fixes, |
791 | see L<perlpolicy>. | |
7f4ffa9d | 792 | |
9d68b7ed LB |
793 | To commit to a maintenance version of perl, you need to create a local |
794 | tracking branch: | |
795 | ||
796 | % git checkout --track -b maint-5.005 origin/maint-5.005 | |
797 | ||
0549aefb LB |
798 | This creates a local branch named C<maint-5.005>, which tracks the |
799 | remote branch C<origin/maint-5.005>. Then you can pull, commit, merge | |
800 | and push as before. | |
b0d36535 | 801 | |
f755e97d | 802 | You can also cherry-pick commits from blead and another branch, by |
0549aefb LB |
803 | using the C<git cherry-pick> command. It is recommended to use the |
804 | B<-x> option to C<git cherry-pick> in order to record the SHA1 of the | |
805 | original commit in the new commit message. | |
f755e97d | 806 | |
04c692a8 DR |
807 | Before pushing any change to a maint version, make sure you've |
808 | satisfied the steps in L</Committing to blead> above. | |
edcf105d | 809 | |
3afc3118 SH |
810 | =head2 Using a smoke-me branch to test changes |
811 | ||
812 | Sometimes a change affects code paths which you cannot test on the OSes | |
813 | which are directly available to you and it would be wise to have users | |
814 | on other OSes test the change before you commit it to blead. | |
815 | ||
816 | Fortunately, there is a way to get your change smoke-tested on various | |
817 | OSes: push it to a "smoke-me" branch and wait for certain automated | |
818 | smoke-testers to report the results from their OSes. | |
9b91093d | 819 | A "smoke-me" branch is identified by the branch name: specifically, as |
47ef154c | 820 | seen on github.com it must be a local branch whose first name |
9b91093d | 821 | component is precisely C<smoke-me>. |
3afc3118 SH |
822 | |
823 | The procedure for doing this is roughly as follows (using the example of | |
a3815e44 | 824 | tonyc's smoke-me branch called win32stat): |
3afc3118 SH |
825 | |
826 | First, make a local branch and switch to it: | |
827 | ||
828 | % git checkout -b win32stat | |
829 | ||
830 | Make some changes, build perl and test your changes, then commit them to | |
831 | your local branch. Then push your local branch to a remote smoke-me | |
832 | branch: | |
833 | ||
834 | % git push origin win32stat:smoke-me/tonyc/win32stat | |
835 | ||
836 | Now you can switch back to blead locally: | |
837 | ||
838 | % git checkout blead | |
839 | ||
840 | and continue working on other things while you wait a day or two, | |
841 | keeping an eye on the results reported for your smoke-me branch at | |
842 | L<http://perl.develop-help.com/?b=smoke-me/tonyc/win32state>. | |
843 | ||
844 | If all is well then update your blead branch: | |
845 | ||
846 | % git pull | |
847 | ||
848 | then checkout your smoke-me branch once more and rebase it on blead: | |
849 | ||
850 | % git rebase blead win32stat | |
851 | ||
852 | Now switch back to blead and merge your smoke-me branch into it: | |
853 | ||
854 | % git checkout blead | |
855 | % git merge win32stat | |
856 | ||
857 | As described earlier, if there are many changes on your smoke-me branch | |
858 | then you should prepare a merge commit in which to give an overview of | |
859 | those changes by using the following command instead of the last | |
860 | command above: | |
861 | ||
862 | % git merge win32stat --no-ff --no-commit | |
863 | ||
864 | You should now build perl and test your (merged) changes one last time | |
865 | (ideally run the whole test suite, but failing that at least run the | |
866 | F<t/porting/*.t> tests) before pushing your changes as usual: | |
867 | ||
868 | % git push origin blead | |
869 | ||
870 | Finally, you should then delete the remote smoke-me branch: | |
871 | ||
872 | % git push origin :smoke-me/tonyc/win32stat | |
873 | ||
874 | (which is likely to produce a warning like this, which can be ignored: | |
875 | ||
c7956846 KW |
876 | remote: fatal: ambiguous argument |
877 | 'refs/heads/smoke-me/tonyc/win32stat': | |
878 | unknown revision or path not in the working tree. | |
879 | remote: Use '--' to separate paths from revisions | |
3afc3118 SH |
880 | |
881 | ) and then delete your local branch: | |
882 | ||
883 | % git branch -d win32stat |