=encoding utf8
=
for
comment
Consistent formatting of this file is achieved
with
:
perl ./Porting/podtidy pod/perlgit.pod
=head1 NAME
perlgit - Detailed information about git and the Perl repository
=head1 DESCRIPTION
This document provides details on using git to develop Perl. If you are
just interested in working on a quick patch, see L<perlhack> first.
This document is intended
for
people who are regular contributors to
Perl, including those
with
write
access to the git repository.
=head1 CLONING THE REPOSITORY
All of Perl's source code is kept centrally in a Git repository at
I<github.com>.
You can make a
read
-only clone of the repository by running:
% git clone git
@github
.com:Perl/perl5.git perl
If you cannot
use
that
for
firewall reasons, you can also clone via http:
=head1 WORKING WITH THE REPOSITORY
Once you have changed into the repository directory, you can inspect
it. After a clone the repository will contain a single
local
branch,
which will be the current branch as well, as indicated by the asterisk.
% git branch
* blead
Using the -a switch to C<branch> will also show the remote tracking
branches in the repository:
% git branch -a
* blead
origin/HEAD
origin/blead
...
The branches that begin
with
"origin"
correspond to the
"git remote"
that you cloned from (which is named
"origin"
). Each branch on the
remote will be exactly tracked by these branches. You should NEVER
do
work on these remote tracking branches. You only ever
do
work in a
local
branch. Local branches can be configured to automerge (on pull)
from a designated remote tracking branch. This is the case
with
the
default
branch C<blead> which will be configured to merge from the
remote tracking branch C<origin/blead>.
You can see recent commits:
% git
log
And pull new changes from the repository, and update your
local
repository (must be clean first)
% git pull
Assuming we are on the branch C<blead> immediately
after
a pull, this
command would be more or less equivalent to:
% git fetch
% git merge origin/blead
In fact
if
you want to update your
local
repository without touching
your working directory you
do
:
% git fetch
And
if
you want to update your remote-tracking branches
for
all
defined
remotes simultaneously you can
do
% git remote update
Neither of these
last
two commands will update your working directory,
however both will update the remote-tracking branches in your
repository.
To make a
local
branch of a remote branch:
% git checkout -b maint-5.10 origin/maint-5.10
To switch back to blead:
% git checkout blead
=head2 Finding out your status
The most common git command you will
use
will probably be
% git status
This command will produce as output a description of the current state
of the repository, including modified files and unignored untracked
files, and in addition it will show things like what files have been
staged
for
the
next
commit, and usually some useful information about
how to change things. For instance the following:
% git status
On branch blead
Your branch is ahead of
'origin/blead'
by 1 commit.
Changes to be committed:
(
use
"git reset HEAD <file>..."
to unstage)
modified: pod/perlgit.pod
Changes not staged
for
commit:
(
use
"git add <file>..."
to update what will be committed)
(
use
"git checkout -- <file>..."
to discard changes in working
directory)
modified: pod/perlgit.pod
Untracked files:
(
use
"git add <file>..."
to include in what will be committed)
deliberate.untracked
This shows that there were changes to this document staged
for
commit,
and that there were further changes in the working directory not yet
staged. It also shows that there was an untracked file in the working
directory, and as you can see shows how to change all of this. It also
shows that there is one commit on the working branch C<blead> which
has
not been pushed to the C<origin> remote yet. B<NOTE>: This output
is also what you see as a template
if
you
do
not provide a message to
C<git commit>.
=head2 Patch workflow
First, please
read
L<perlhack>
for
details on hacking the Perl core.
That document covers many details on how to create a good patch.
If you already have a Perl repository, you should ensure that you're on
the I<blead> branch, and your repository is up to date:
% git checkout blead
% git pull
It's preferable to patch against the latest blead version, since this
is where new development occurs
for
all changes other than critical bug
fixes. Critical bug fix patches should be made against the relevant
maint branches, or should be submitted
with
a note indicating all the
branches where the fix should be applied.
Now that we have everything up to date, we need to create a temporary
new branch
for
these changes and switch into it:
% git checkout -b orange
which is the short form of
% git branch orange
% git checkout orange
Creating a topic branch makes it easier
for
the maintainers to rebase
or merge back into the master blead
for
a more linear history. If you
don't work on a topic branch the maintainer
has
to manually cherry pick
your changes onto blead
before
they can be applied.
That
'll get you scolded on perl5-porters, so don'
t
do
that. Be Awesome.
Then make your changes. For example,
if
Leon Brocard changes his name
to Orange Brocard, we should change his name in the AUTHORS file:
% perl -pi -e
's{Leon Brocard}{Orange Brocard}'
AUTHORS
You can see what files are changed:
% git status
On branch orange
Changes to be committed:
(
use
"git reset HEAD <file>..."
to unstage)
modified: AUTHORS
And you can see the changes:
% git diff
diff --git a/AUTHORS b/AUTHORS
index
293dd70..722c93e 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -541,7 +541,7 @@ Lars Hecking <lhecking
@nmrc
.ucc.ie>
Laszlo Molnar <laszlo.molnar
@eth
.ericsson.se>
Leif Huhn <leif
@hale
.dkstat.com>
Len Johnson <lenjay
@ibm
.net>
-Leon Brocard <acme
@astray
.com>
+Orange Brocard <acme
@astray
.com>
Les Peters <lpeters
@aol
.net>
Lesley Binks <lesley.binks
@gmail
.com>
Lincoln D. Stein <lstein
@cshl
.org>
Now commit your change locally:
% git commit -a -m
'Rename Leon Brocard to Orange Brocard'
Created commit 6196c1d: Rename Leon Brocard to Orange Brocard
1 files changed, 1 insertions(+), 1 deletions(-)
The C<-a> option is used to include all files that git tracks that you
have changed. If at this
time
, you only want to commit some of the
files you have worked on, you can omit the C<-a> and
use
the command
C<S<git add I<FILE ...>>>
before
doing the commit. C<S<git add
--interactive>> allows you to even just commit portions of files
instead of all the changes in them.
The C<-m> option is used to specify the commit message. If you omit it,
git will
open
a text editor
for
you to compose the message
interactively. This is useful
when
the changes are more complex than
the sample
given
here, and, depending on the editor, to know that the
first line of the commit message doesn't exceed the 50 character legal
maximum. See L<perlhack/Commit message>
for
more information about what
makes a good commit message.
Once you've finished writing your commit message and exited your
editor, git will
write
your change to disk and
tell
you something like
this:
Created commit daf8e63: explain git status and stuff about remotes
1 files changed, 83 insertions(+), 3 deletions(-)
If you re-run C<git status>, you should see something like this:
% git status
On branch orange
Untracked files:
(
use
"git add <file>..."
to include in what will be committed)
deliberate.untracked
nothing added to commit but untracked files present (
use
"git add"
to
track)
When in doubt,
before
you
do
anything
else
, check your status and
read
it carefully, many questions are answered directly by the git status
output.
You can examine your
last
commit
with
:
% git show HEAD
and
if
you are not happy
with
either the description or the patch
itself you can fix it up by editing the files once more and then issue:
% git commit -a --amend
Now, create a
fork
on GitHub to
push
your branch to, and add it as a
remote
if
you haven't already, as described in the GitHub documentation
% git remote add
fork
git
@github
.com:MyUser/perl5.git
And
push
the branch to your
fork
:
% git
push
-u
fork
orange
You should now submit a Pull Request (PR) on GitHub from the new branch
to blead. For more information, see the GitHub documentation at
You can also
send
patch files to
L<perl5-porters
@perl
.org|mailto:perl5-porters
@perl
.org> directly
if
the
patch is not ready to be applied, but intended
for
discussion.
To create a patch file
for
all your
local
changes:
% git
format
-patch -M blead..
0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
Or
for
a lot of changes, e.g. from a topic branch:
% git
format
-patch --stdout -M blead.. > topic-branch-changes.patch
If you want to
delete
your temporary branch, you may
do
so
with
:
% git checkout blead
% git branch -d orange
error: The branch
'orange'
is not an ancestor of your current HEAD.
If you are sure you want to
delete
it, run
'git branch -D orange'
.
% git branch -D orange
Deleted branch orange.
=head2 A note on derived files
Be aware that many files in the distribution are derivative--avoid
patching them, because git won't see the changes to them, and the build
process will overwrite them. Patch the originals instead. Most
utilities (like perldoc) are in this category, i.e. patch
F<utils/perldoc.PL> rather than F<utils/perldoc>. Similarly, don't
create patches
for
files under F<
$src_root
/ext> from their copies found
in F<
$install_root
/lib>. If you are unsure about the proper location of
a file that may have gotten copied
while
building the source
distribution, consult the F<MANIFEST>.
=head2 Cleaning a working directory
The command C<git clean> can
with
varying arguments be used as a
replacement
for
C<make clean>.
To
reset
your working directory to a pristine condition you can
do
:
% git clean -dxf
However, be aware this will
delete
ALL untracked content. You can
use
% git clean -Xf
to remove all ignored untracked files, such as build and test
byproduct, but leave any manually created files alone.
If you only want to cancel some uncommitted edits, you can
use
C<git
checkout> and give it a list of files to be reverted, or C<git checkout
-f> to revert them all.
If you want to cancel one or several commits, you can
use
C<git
reset
>.
=head2 Bisecting
C<git> provides a built-in way to determine which commit should be blamed
for
introducing a
given
bug. C<git bisect> performs a binary search of
history to locate the first failing commit. It is fast, powerful and
flexible, but requires some setup and to automate the process an auxiliary
shell script is needed.
The core provides a wrapper program, F<Porting/bisect.pl>, which attempts to
simplify as much as possible, making bisecting as simple as running a Perl
one-liner. For example,
if
you want to know
when
this became an error:
perl -e
'my $a := 2'
you simply run this:
.../Porting/bisect.pl -e
'my $a := 2;'
Using F<Porting/bisect.pl>,
with
one command (and
no
other files) it's easy to
find out
=over 4
=item *
Which commit caused this example code to break?
=item *
Which commit caused this example code to start working?
=item *
Which commit added the first file to match this regex?
=item *
Which commit removed the
last
file to match this regex?
=back
usually without needing to know which versions of perl to
use
as start and
end revisions, as F<Porting/bisect.pl> automatically searches to find the
earliest stable version
for
which the test case passes. Run
C<Porting/bisect.pl --help>
for
the full documentation, including how to
set the C<Configure> and build
time
options.
If you
require
more flexibility than F<Porting/bisect.pl>
has
to offer, you'll
need to run C<git bisect> yourself. It's most useful to
use
C<git bisect run>
to automate the building and testing of perl revisions. For this you'll need
a shell script
for
C<git> to call to test a particular revision. An example
script is F<Porting/bisect-example.sh>, which you should copy B<outside> of
the repository, as the bisect process will
reset
the state to a clean checkout
as it runs. The instructions below assume that you copied it as F<~/run> and
then edited it as appropriate.
You first enter in bisect mode
with
:
% git bisect start
For example,
if
the bug is present on C<HEAD> but wasn't in 5.10.0,
C<git> will learn about this
when
you enter:
% git bisect bad
% git bisect good perl-5.10.0
Bisecting: 853 revisions left to test
after
this
This results in checking out the median commit between C<HEAD> and
C<perl-5.10.0>. You can then run the bisecting process
with
:
% git bisect run ~/run
When the first bad commit is isolated, C<git bisect> will
tell
you so:
ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit
commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5
Author: Dave Mitchell <davem
@fdisolutions
.com>
Date: Sat Feb 9 14:56:23 2008 +0000
[perl
...
bisect run success
You can peek into the bisecting process
with
C<git bisect
log
> and
C<git bisect visualize>. C<git bisect
reset
> will get you out of bisect
mode.
Please note that the first C<good> state must be an ancestor of the
first C<bad> state. If you want to search
for
the commit that I<solved>
some bug, you have to negate your test case (i.e.
exit
with
C<1>
if
OK
and C<0>
if
not) and still mark the lower bound as C<good> and the
upper as C<bad>. The
"first bad commit"
has
then to be understood as
the
"first commit where the bug is solved"
.
C<git help bisect>
has
much more information on how you can tweak your
binary searches.
Following bisection you may wish to configure, build and test perl at
commits identified by the bisection process. Sometimes, particularly
with
older perls, C<make> may fail during this process. In this case
you may be able to patch the source code at the older commit point. To
do
so, please follow the suggestions provided in
L<perlhack/Building perl at older commits>.
=head2 Topic branches and rewriting history
Individual committers should create topic branches under
B<yourname>/B<some_descriptive_name>:
% branch=
"$yourname/$some_descriptive_name"
% git checkout -b
$branch
...
do
local
edits, commits etc ...
% git
push
origin -u
$branch
Should you be stuck
with
an ancient version of git (prior to 1.7), then
C<git
push
> will not have the C<-u> switch, and you have to replace the
last
step
with
the following sequence:
% git
push
origin
$branch
:refs/heads/
$branch
% git config branch.
$branch
.remote origin
% git config branch.
$branch
.merge refs/heads/
$branch
If you want to make changes to someone
else
's topic branch, you should
check
with
its creator
before
making any change to it.
You
might sometimes find that the original author
has
edited the branch's
history. There are lots of good reasons
for
this. Sometimes, an author
might simply be rebasing the branch onto a newer source point.
Sometimes, an author might have found an error in an early commit which
they wanted to fix
before
merging the branch to blead.
Currently the master repository is configured to forbid
non-fast-forward merges. This means that the branches within can not be
rebased and pushed as a single step.
The only way you will ever be allowed to rebase or modify the history
of a pushed branch is to
delete
it and
push
it as a new branch under
the same name. Please think carefully about doing this. It may be
better to sequentially
rename
your branches so that it is easier
for
others working
with
you to cherry-pick their
local
changes onto the new
version. (XXX: needs explanation).
If you want to rebase a personal topic branch, you will have to
delete
your existing topic branch and
push
as a new version of it. You can
do
this via the following formula (see the explanation about C<refspec>'s
in the git
push
documentation
for
details)
after
you have rebased your
branch:
% git checkout
$user
/
$topic
% git fetch
% git rebase origin/blead
% git
push
origin :
$user
/
$topic
% git
push
origin
$user
/
$topic
B<NOTE:> it is forbidden at the repository level to
delete
any of the
"primary"
branches. That is any branch matching
C<m!^(blead|maint|perl)!>. Any attempt to
do
so will result in git
producing an error like this:
% git
push
origin :blead
*** It is forbidden to
delete
blead/maint branches in this repository
error: hooks/update exited
with
error code 1
error: hook declined to update refs/heads/blead
! [remote rejected] blead (hook declined)
As a matter of policy we
do
B<not> edit the history of the blead and
maint-* branches. If a typo (or worse) sneaks into a commit to blead or
maint-*, we'll fix it in another commit. The only types of updates
allowed on these branches are
"fast-forwards"
, where all history is
preserved.
Annotated tags in the canonical perl.git repository will never be
deleted or modified. Think long and hard about whether you want to
push
a
local
tag to perl.git
before
doing so. (Pushing simple tags is
not allowed.)
=head2 Grafts
The perl history contains one mistake which was not caught in the
conversion: a merge was recorded in the history between blead and
maint-5.10 where
no
merge actually occurred. Due to the nature of git,
this is now impossible to fix in the public repository. You can remove
this mis-merge locally by adding the following line to your
C<.git/info/grafts> file:
296f12bbbbaa06de9be9d09d3dcf8f4528898a49 434946e0cb7a32589ed92d18008aaa1d88515930
It is particularly important to have this graft line
if
any bisecting
is done in the area of the
"merge"
in question.
=head1 WRITE ACCESS TO THE GIT REPOSITORY
Once you have
write
access, you will need to modify the URL
for
the
origin remote to enable pushing. Edit F<.git/config>
with
the
git-config(1) command:
% git config remote.origin.url git
@github
.com:Perl/perl5.git
You can also set up your user name and e-mail address. Most people
do
this once globally in their F<~/.gitconfig> by doing something like:
% git config --global user.name
"Ævar Arnfjörð Bjarmason"
% git config --global user.email avarab
@gmail
.com
However,
if
you'd like to
override
that just
for
perl,
execute something like the following in F<perl>:
% git config user.email avar
@cpan
.org
It is also possible to keep C<origin> as a git remote, and add a new
remote
for
ssh access:
% git remote add camel git
@github
.com:Perl/perl5.git
This allows you to update your
local
repository by pulling from
C<origin>, which is faster and doesn't
require
you to authenticate, and
to
push
your changes back
with
the C<camel> remote:
% git fetch camel
% git
push
camel
The C<fetch> command just updates the C<camel> refs, as the objects
themselves should have been fetched
when
pulling from C<origin>.
=head2 Working
with
Github pull requests
Pull requests typically originate from outside of the C<Perl/perl.git>
repository, so
if
you want to test or work
with
it locally a vanilla
C<git fetch> from the C<Perl/perl5.git> repository won't fetch it.
However Github does provide a mechanism to fetch a pull request to a
local
branch. They are available on Github remotes under C<pull/>, so
you can
use
C<< git fetch pull/I<PRID>/head:I<localname> >> to make a
local
copy. eg. to fetch pull request 9999 to the
local
branch
C<
local
-branch-name> run:
git fetch origin pull/9999/head:
local
-branch-name
and then:
git checkout
local
-branch-name
Note: this branch is not rebased on C<blead>, so instead of the
checkout above, you might want:
git rebase origin/blead
local
-branch-name
which rebases C<
local
-branch-name> on C<blead>, and checks it out.
Alternatively you can configure the remote to fetch all pull requests
as remote-tracking branches. To
do
this edit the remote in
F<.git/config>,
for
example
if
your github remote is C<origin> you'd
have:
[remote
"origin"
]
url = git
@github
.com:/Perl/perl5.git
fetch = +refs/heads/*:refs/remotes/origin/*
Add a line to
map
the remote pull request branches to remote-tracking
branches:
[remote
"origin"
]
url = git
@github
.com:/Perl/perl5.git
fetch = +refs/heads/*:refs/remotes/origin/*
fetch = +refs/pull/*/head:refs/remotes/origin/pull/*
and then
do
a fetch as normal:
git fetch origin
This will create a remote-tracking branch
for
every pull request, including
closed requests.
To remove those remote-tracking branches, remove the line added above
and prune:
git fetch -p origin
=head2 Accepting a patch
If you have received a patch file generated using the above section,
you should
try
out the patch.
First we need to create a temporary new branch
for
these changes and
switch into it:
% git checkout -b experimental
Patches that were formatted by C<git
format
-patch> are applied
with
C<git am>:
% git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
Applying Rename Leon Brocard to Orange Brocard
Note that some UNIX mail systems can mess
with
text attachments containing
'From '
. This will fix them up:
% perl -pi -e
's/^>From /From /'
\
0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
If just a raw diff is provided, it is also possible
use
this two-step
process:
% git apply bugfix.diff
% git commit -a -m
"Some fixing"
\
--author=
"That Guy <that.guy@internets.com>"
Now we can inspect the change:
% git show HEAD
commit b1b3dab48344cff6de4087efca3dbd63548ab5e2
Author: Leon Brocard <acme
@astray
.com>
Date: Fri Dec 19 17:02:59 2008 +0000
Rename Leon Brocard to Orange Brocard
diff --git a/AUTHORS b/AUTHORS
index
293dd70..722c93e 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -541,7 +541,7 @@ Lars Hecking <lhecking
@nmrc
.ucc.ie>
Laszlo Molnar <laszlo.molnar
@eth
.ericsson.se>
Leif Huhn <leif
@hale
.dkstat.com>
Len Johnson <lenjay
@ibm
.net>
-Leon Brocard <acme
@astray
.com>
+Orange Brocard <acme
@astray
.com>
Les Peters <lpeters
@aol
.net>
Lesley Binks <lesley.binks
@gmail
.com>
Lincoln D. Stein <lstein
@cshl
.org>
If you are a committer to Perl and you think the patch is good, you can
then merge it into blead then
push
it out to the main repository:
% git checkout blead
% git merge experimental
% git
push
origin blead
If you want to
delete
your temporary branch, you may
do
so
with
:
% git checkout blead
% git branch -d experimental
error: The branch
'experimental'
is not an ancestor of your current
HEAD. If you are sure you want to
delete
it, run 'git branch -D
experimental'.
% git branch -D experimental
Deleted branch experimental.
=head2 Committing to blead
The
'blead'
branch will become the
next
production release of Perl.
Before pushing I<any>
local
change to blead, it's incredibly important
that you
do
a few things, lest other committers come
after
you
with
pitchforks and torches:
=over
=item *
Make sure you have a good commit message. See L<perlhack/Commit
message>
for
details.
=item *
Run the test suite. You might not think that one typo fix would break a
test file. You
'd be wrong. Here'
s an example of where not running the
suite caused problems. A patch was submitted that added a couple of
tests to an existing F<.t>. It couldn't possibly affect anything
else
, so
no
need to test beyond the single affected F<.t>, right? But, the
submitter's email address had changed since the
last
of their
submissions, and this caused other tests to fail. Running the test
target
given
in the
next
item would have caught this problem.
=item *
If you don't run the full test suite, at least C<make test_porting>.
This will run basic sanity checks. To see which sanity checks, have a
look in F<t/porting>.
=item *
If you make any changes that affect miniperl or core routines that have
different code paths
for
miniperl, be sure to run C<make minitest>.
This will
catch
problems that even the full test suite will not
catch
because it runs a subset of tests under miniperl rather than perl.
=back
=head2 On merging and rebasing
Simple, one-off commits pushed to the
'blead'
branch should be simple
commits that apply cleanly. In other words, you should make sure your
work is committed against the current position of blead, so that you can
push
back to the master repository without merging.
Sometimes, blead will move
while
you're building or testing your
changes. When this happens, your
push
will be rejected
with
a message
like this:
! [rejected] blead -> blead (non-fast-forward)
To prevent you from losing history, non-fast-forward updates were
rejected Merge the remote changes (e.g.
'git pull'
)
before
pushing
again. See the
'Note about fast-forwards'
section of
'git push --help'
for
details.
When this happens, you can just I<rebase> your work against the new
position of blead, like this (assuming your remote
for
the master
repository is
"p5p"
):
% git fetch p5p
% git rebase p5p/blead
You will see your commits being re-applied, and you will then be able to
push
safely. More information about rebasing can be found in the
documentation
for
the git-rebase(1) command.
For larger sets of commits that only make sense together, or that would
benefit from a summary of the set's purpose, you should
use
a merge
commit. You should perform your work on a L<topic branch|/Topic
branches and rewriting history>, which you should regularly rebase
against blead to ensure that your code is not broken by blead moving.
When you have finished your work, please perform a final rebase and
test. Linear history is something that gets lost
with
every
commit on blead, but a final rebase makes the history linear
again, making it easier
for
future maintainers to see what
has
happened. Rebase as follows (assuming your work was on the
branch C<< committer/somework >>):
% git checkout committer/somework
% git rebase blead
Then you can merge it into master like this:
% git checkout blead
% git merge --
no
-ff --
no
-commit committer/somework
% git commit -a
The switches above deserve explanation. C<--
no
-ff> indicates that even
if
all your work can be applied linearly against blead, a merge commit
should still be prepared. This ensures that all your work will be shown
as a side branch,
with
all its commits merged into the mainstream blead
by the merge commit.
C<--
no
-commit> means that the merge commit will be I<prepared> but not
I<committed>. The commit is then actually performed
when
you run the
next
command, which will bring up your editor to describe the commit.
Without C<--
no
-commit>, the commit would be made
with
nearly
no
useful
message, which would greatly diminish the value of the merge commit as a
placeholder
for
the work's description.
When describing the merge commit, explain the purpose of the branch, and
keep in mind that this description will probably be used by the
eventual release engineer
when
reviewing the
next
perldelta document.
=head2 Committing to maintenance versions
Maintenance versions should only be altered to add critical bug fixes,
see L<perlpolicy>.
To commit to a maintenance version of perl, you need to create a
local
tracking branch:
% git checkout --track -b maint-5.005 origin/maint-5.005
This creates a
local
branch named C<maint-5.005>, which tracks the
remote branch C<origin/maint-5.005>. Then you can pull, commit, merge
and
push
as
before
.
You can also cherry-pick commits from blead and another branch, by
using the C<git cherry-pick> command. It is recommended to
use
the
B<-x> option to C<git cherry-pick> in order to record the SHA1 of the
original commit in the new commit message.
Before pushing any change to a maint version, make sure you've
satisfied the steps in L</Committing to blead> above.
=head2 Using a smoke-me branch to test changes
Sometimes a change affects code paths which you cannot test on the OSes
which are directly available to you and it would be wise to have users
on other OSes test the change
before
you commit it to blead.
Fortunately, there is a way to get your change smoke-tested on various
OSes:
push
it to a
"smoke-me"
branch and
wait
for
certain automated
smoke-testers to report the results from their OSes.
A
"smoke-me"
branch is identified by the branch name: specifically, as
seen on github.com it must be a
local
branch whose first name
component is precisely C<smoke-me>.
The procedure
for
doing this is roughly as follows (using the example of
tonyc's smoke-me branch called win32stat):
First, make a
local
branch and switch to it:
% git checkout -b win32stat
Make some changes, build perl and test your changes, then commit them to
your
local
branch. Then
push
your
local
branch to a remote smoke-me
branch:
% git
push
origin win32stat:smoke-me/tonyc/win32stat
Now you can switch back to blead locally:
% git checkout blead
and
continue
working on other things
while
you
wait
a day or two,
keeping an eye on the results reported
for
your smoke-me branch at
If all is well then update your blead branch:
% git pull
then checkout your smoke-me branch once more and rebase it on blead:
% git rebase blead win32stat
Now switch back to blead and merge your smoke-me branch into it:
% git checkout blead
% git merge win32stat
As described earlier,
if
there are many changes on your smoke-me branch
then you should prepare a merge commit in which to give an overview of
those changes by using the following command instead of the
last
command above:
% git merge win32stat --
no
-ff --
no
-commit
You should now build perl and test your (merged) changes one
last
time
(ideally run the whole test suite, but failing that at least run the
F<t/porting/*.t> tests)
before
pushing your changes as usual:
% git
push
origin blead
Finally, you should then
delete
the remote smoke-me branch:
% git
push
origin :smoke-me/tonyc/win32stat
(which is likely to produce a warning like this, which can be ignored:
remote: fatal: ambiguous argument
'refs/heads/smoke-me/tonyc/win32stat'
:
unknown revision or path not in the working tree.
remote: Use
'--'
to separate paths from revisions
) and then
delete
your
local
branch:
% git branch -d win32stat