better document smart match overloading

[p5sagit/p5-mst-13.2.git] / Porting / release_managers_guide.pod

=head1 NAME

release_managers_guide - Releasing a new version of perl 5.x

As of August 2009, this file is mostly complete, although it is missing
some detail on doing a major release (e.g. 5.10.0 -> 5.12.0). Note that
things change at each release, so there may be new things not covered
here, or tools may need updating.

=head1 SYNOPSIS

This document describes the series of tasks required - some automatic, some
manual - to produce a perl release of some description, be that a snaphot,
release candidate, or final, numbered release of maint or blead.

The release process has traditionally been executed by the current
pumpking.

This document both helps as a check-list for the release engineer 
and is a base for ideas on how the various tasks could be automated 
or distributed.

The outline of a typical release cycle is as follows:

    (5.10.1 is released, and post-release actions have been done)

    ...time passes...

    an occasional snapshot is released, that still identifies itself as
	5.10.1

    ...time passes...

    a few weeks before the release, a number of steps are performed,
	including bumping the version to 5.10.2

    ...a few weeks passes...

    perl-5.10.2-RC1 is released

    perl-5.10.2 is released

    post-release actions are performed, including creating new
	perl5103delta.pod

    ... the cycle continues ...

=head1 DETAILS

Some of the tasks described below apply to all four types of 
release of Perl. (snapshot, RC, final release of maint, final 
release of blead). Some of these tasks apply only to a subset
of these release types.  If a step does not apply to a given 
type of release, you will see a notation to that effect at
the beginning of the step.

=head2 Release types

=over 4

=item Snapshot

A snapshot is intended to encourage in-depth testing from time-to-time,
for example after a key point in the stabilisation of a branch. It
requires fewer steps than a full release, and the version number of perl in
the tarball will usually be the same as that of the previous release.

=item Release Candidate (RC)

A release candidate is an attempt to produce a tarball that is a close as
possible to the final release. Indeed, unless critical faults are found
during the RC testing, the final release will be identical to the RC
barring a few minor fixups (updating the release date in F<perlhist.pod>,
removing the RC status from F<patchlevel.h>, etc). If faults are found,
then the fixes should be put into a new release candidate, never directly
into a final release.

=item Stable/Maint release

At this point you should have a working release candidate with few or no
changes since.

It's essentially the same procedure as for making a release candidate, but
with a whole bunch of extra post-release steps.

=item Blead release

It's essentially the same procedure as for making a release candidate, but
with a whole bunch of extra post-release steps.

=back

=head2 Prerequisites

Before you can make an official release of perl, there are a few
hoops you need to jump through:

=over 4

=item PAUSE account

I<SKIP this step for SNAPSHOT>

Make sure you have a PAUSE account suitable for uploading a perl release.
If you don't have a PAUSE account, then request one:

    https://pause.perl.org/pause/query?ACTION=request_id

Check that your account is allowed to upload perl distros: goto
https://pause.perl.org/, login, then select 'upload file to CPAN'; there
should be a "For pumpkings only: Send a CC" tickbox.  If not, ask Andreas
König to add your ID to the list of people allowed to upload something
called perl.  You can find Andreas' email address at:

    https://pause.perl.org/pause/query?ACTION=pause_04imprint

=item CPAN mirror

Some release engineering steps require a full mirror of the CPAN.
Work to fall back to using a remote mirror via HTTP is incomplete
but ongoing. (No, a minicpan mirror is not sufficient)

=item git checkout and commit bit

You will need a working C<git> installation, checkout of the perl
git repository and perl commit bit.  For information about working
with perl and git, see F<pod/perlrepository.pod>.

If you are not yet a perl committer, you won't be able to make a
release.  Have a chat with whichever evil perl porter tried to talk
you into the idea in the first place to figure out the best way to
resolve the issue.


=item Quotation for release announcement epigraph

I<SKIP this step for SNAPSHOT and RC>

For a numbered blead or maint release of perl, you will need a quotation 
to use as an epigraph to your release announcement.  (There's no harm
in having one for a snapshot, but it's not required).


=back


=head2 Building a release - advance actions

The work of building a release candidate for a numbered release of
perl generally starts several weeks before the first release candidate.
Some of these should be done regularly, but all I<must> be done in the 
runup to a release.

=over 4

=item *

I<You MAY SKIP this step for SNAPSHOT>

Ensure that dual-life CPAN modules are synchronised with CPAN.  Basically,
run the following:

    $ ./perl -Ilib Porting/core-cpan-diff -a -o /tmp/corediffs

to see any inconsistencies between the core and CPAN versions of distros,
then fix the core, or cajole CPAN authors as appropriate. See also the
C<-d> and C<-v> options for more detail.  You'll probably want to use the
C<-c cachedir> option to avoid repeated CPAN downloads.

To see which core distro versions differ from the current CPAN versions:

    $ ./perl -Ilib Porting/core-cpan-diff -x -a

if you are making a maint release, run C<core-cpan-diff> on both blead and
maint, then diff the two outputs. Compare this with what you expect, and if
necessary, fix things up. For example, you might think that both blead
and maint are synchronised with a particular CPAN module, but one might
have some extra changes. 

=item *

I<You MAY SKIP this step for SNAPSHOT>

Ensure dual-life CPAN modules are stable, which comes down to:

    for each module that fails its regression tests on $current
        did it fail identically on $previous?
        if yes, "SEP" (Somebody Else's Problem)
        else work out why it failed (a bisect is useful for this)

    attempt to group failure causes

    for each failure cause
        is that a regression?
        if yes, figure out how to fix it
            (more code? revert the code that broke it)
        else
            (presumably) it's relying on something un-or-under-documented
            should the existing behaviour stay?
                yes - goto "regression"
                no - note it in perldelta as a significant bugfix
                (also, try to inform the module's author)

=item *

I<You MAY SKIP this step for SNAPSHOT>

Similarly, monitor the smoking of core tests, and try to fix.

=item *

I<You MAY SKIP this step for SNAPSHOT>

Similarly, monitor the smoking of perl for compiler warnings, and try to
fix.

=item *

I<You MAY SKIP this step for SNAPSHOT>

Run F<Porting/cmpVERSION.pl> to compare the current source tree with the
previous version to check for for modules that have identical version
numbers but different contents, e.g.:

     $ cd ~/some-perl-root
     $ ./perl -Ilib Porting/cmpVERSION.pl -xd ~/my_perl-tarballs/perl-5.10.0 .

then bump the version numbers of any non-dual-life modules that have
changed since the previous release, but which still have the old version
number. If there is more than one maintenance branch (e.g. 5.8.x, 5.10.x),
then compare against both.

Note that some of the files listed may be generated (e.g. copied from ext/
to lib/, or a script like lib/lib_pm.PL is run to produce lib/lib.pm);
make sure you edit the correct file!

Once all version numbers have been bumped, re-run the checks.

Then run again without the -x option, to check that dual-life modules are
also sensible.

=item *

I<You MAY SKIP this step for SNAPSHOT>

Get perldelta in a mostly finished state.

Peruse  F<Porting/how_to_write_a_perldelta.pod>, and try to make sure that
every section it lists is, if necessary, populated and complete. Copy
edit the whole document.

=item *

I<You MUST SKIP this step for SNAPSHOT>

A week or two before the first release candidate, bump the perl version
number (e.g. from 5.10.0 to 5.10.1), to allow sufficient time for testing
and smoking with the target version built into the perl executable. For
subsequent release candidates and the final release, it it not necessary
to bump the version further.

There is a tool to semi-automate this process. It works in two stages.
First, it generates a list of suggested changes, which you review and
edit; then you feed this list back and it applies the edits. So, first
scan the source dir looking for likely  candidates:

    $ Porting/bump-perl-version -s 5.10.0 5.10.1 > /tmp/scan

This produces a file containing a list of suggested edits, eg:

    NetWare/Makefile

       89: -MODULE_DESC     = "Perl 5.10.0 for NetWare"
	   +MODULE_DESC     = "Perl 5.10.1 for NetWare"

i.e. in the file F<NetWare/Makefile>, line 89 would be changed as shown.
Review the file carefully, and delete any -/+ line pairs that you don't
want changing. Remember that this tool is largely just grepping for '5.10.0'
or whatever, so it will generate false positives. Be careful not change
text like "this was fixed in 5.10.0"! Then run:

    $ Porting/bump-perl-version -u < /tmp/scan

which will update all the files shown; then commit the changes.

Be particularly careful with F<INSTALL>, which contains a mixture of
C<5.10.0>-type strings, some of which need bumping on every release, and
some of which need to be left. Also note that this tool currently only
performs a single change per line, so in particular, this line in
README.vms needs special handling:

    rename perl-5^.10^.1.dir perl-5_10_1.dir


=item *

I<You MUST SKIP this step for SNAPSHOT>

Review and update INSTALL to account for the change in version number;
in particular, the "Coexistence with earlier versions of perl 5" section.

=item *

I<You MUST SKIP this step for SNAPSHOT>

Update the F<Changes> file to contain the git log command which would show
all the changes in this release. You will need assume the existence of a
not-yet created tag for the forthcoming release; e.g.

    git log ... perl-5.10.0..perl5.12.0

Due to warts in the perforce-to-git migration, some branches require extra
exclusions to avoid other branches being pulled in. Make sure you have the
correct incantation: replace the not-yet-created tag with C<HEAD> and see
if git log produces roughly the right number of commits across roughly the
right time period.


=item *

Check some more build configurations, e.g.

     -Duseshrplib -Dd_dosuid
     make suidperl

Check that setuid installs works (for < 5.11.0 only).
XXX any other configs?


=item *

I<You MAY SKIP this step for SNAPSHOT>

Update F<AUTHORS>, using the C<Porting/checkAUTHORS.pl> script, and if
necessary, update the script to include new alias mappings for porters
already in F<AUTHORS>

	$ git log | perl Porting/checkAUTHORS.pl --acknowledged AUTHORS -

=item *

I<You MAY SKIP this step for SNAPSHOT>

As there are no regular smokes [ XXX yet - please fix?] find out about the
state of the current branch on VMS. If the branch you're releasing on
is failing tests on VMS, you may not want to do a release.

=back

=head2 Building a release - on the day

This section describes the actions required to make a release (or snapshot
etc) that are performed on the actual day.

=over 4

=item *

Review all the items in the previous section,
L<"Building a release - advance actions"> to ensure they are all done and
up-to-date.

=item *

I<You MAY SKIP this step for SNAPSHOT>

Re-read the perldelta to try to find any embarrassing typos and thinkos;
remove any C<TODO> or C<XXX> flags; update the "Known Problems" section
with any serious issues for which fixes are not going to happen now; and
run through pod and spell checkers, e.g.

    $ podchecker -warnings -warnings pod/perl5101delta.pod
    $ spell pod/perl5101delta.pod

Also, you may want to generate and view an HTML version of it to check
formatting, e.g.

    $ perl pod/pod2html pod/perl5101delta.pod > /tmp/perl5101delta.html

=item *

Make sure you have a gitwise-clean perl directory (no modified files,
unpushed commits etc):

    $ git status

=item *

If not already built, Configure and build perl so that you have a Makefile
and porting tools:

    $ ./Configure -Dusedevel -des
    $ make

=item *

Check that files managed by F<regen.pl> and friends are up to date. From
within your working directory:

    $ git status
    $ make regen
    $ make regen_perly
    $ git status

If any of the files managed by F<regen.pl> have changed, then you should
re-make perl to check that it's okay, then commit the updated versions:

    $ git commit -a -m 'make regn; make regn_perly'

=item *

Rebuild META.yml:

    $ rm META.yml
    $ make META.yml
    $ git diff

XXX it would be nice to make Porting/makemeta use regen_lib.pl
to get the same 'update the file if its changed' functionality
we get with 'make regen' etc.

Commit META.yml if it has changed:

    $ git commit -m 'Update META.yml' META.yml

=item *

I<You MUST SKIP this step for SNAPSHOT>

Update C<Module::Corelist>.

Note that if this is a maint release, you should run the following actions
from the maint directory, but commit the C<Corelist.pm> changes in
I<blead> and subsequently cherry-pick it.

F<corelist.pl> uses ftp.funet.fi to verify information about dual-lived
modules on CPAN. It can use a full, local CPAN mirror or fall back
to C<wget> or C<curl> to fetch only package metadata remotely.

(If you'd prefer to have a full CPAN mirror, see 
http://www.cpan.org/misc/cpan-faq.html#How_mirror_CPAN)

Then change to your perl checkout, and if necessary,

    $ make perl

Then, If you have a local CPAN mirror, run:

    $ ./perl -Ilib Porting/corelist.pl ~/my-cpan-mirror

Otherwise, run:

    $ ./perl -Ilib Porting/corelist.pl cpan

This will chug for a while. Assuming all goes well, it will
update F<lib/Module/CoreList.pm>.

Check that file over carefully:

    $ git diff lib/Module/CoreList.pm

In particular, if this not the first update for this version, make sure
that there isn't a duplicated entry (e.g. '5.010001' entries for both RC1
and RC2).

XXX the edit-in-place functionality of Porting/corelist.pl should
be fixed to allow for this

If necessary, bump C<$VERSION> (there's no need to do this for
every RC; in RC1, bump the version to a new clean number that will
appear in the final release, and leave as-is for the later RCs and final).

Edit the version number in the new C<< 'Module::CoreList' => 'X.YZ' >>
entry, as that is likely to reflect the previous version number.

In addition, if this is a final release (rather than a release candidate):

=over 4 

=item *

Update this version's entry in the C<%released> hash with today's date.

=item *

Make sure that the script has correctly updated the C<CAVEATS> section

=back

Finally, commit the new version of Module::CoreList:
(unless this is for maint; in which case commit it blead first, then
cherry-pick it back).

    $ git commit -m 'Updated Module::CoreList for the 5.x.y release' \
     lib/Module/CoreList.pm


=item *

Check that the manifest is sorted and correct:

    $ make manisort
    $ make distclean
    $ perl Porting/manicheck

Commit MANIFEST if it has changed:

    $ git commit -m 'Update MANIFEST' MANIFEST

=item *

I<You MUST SKIP this step for SNAPSHOT>

Add an entry to F<pod/perlhist.pod> with the current date, e.g.:

    David    5.10.1-RC1    2009-Aug-06

Make sure that the correct pumpking is listed in the left-hand column, and
if this is the first release under the stewardship of a new pumpking, make
sure that his or her name is listed in the section entitled
C<THE KEEPERS OF THE PUMPKIN>.

Be sure to commit your changes:

    $ git commit -m 'add new release to perlhist' pod/perlhist.pod

=item *

I<You MUST SKIP this step for SNAPSHOT>

Update F<patchlevel.h> to add a C<-RC1>-or-whatever string; or, if this is
a final release, remove it. For example:

     static const char * const local_patches[] = {
             NULL
    +        ,"RC1"
             PERL_GIT_UNPUSHED_COMMITS /* do not remove this line */

Be sure to commit your change:

    $ git commit -m 'bump version to RCnnn' patchlevel.h

=item *

Build perl, then make sure it passes its own test suite, and installs:

    $ git clean -xdf
    $ ./Configure -des -Dprefix=/tmp/perl-5.x.y-pretest

    # or if it's an odd-numbered version:
    $ ./Configure -des -Dusedevel -Dprefix=/tmp/perl-5.x.y-pretest

    $ make test install

=item *

Check that the output of C<perl -v> and C<perl -V> are as expected,
especially as regards version numbers, patch and/or RC levels, and @INC
paths.

=item *

Push all your recent commits:

    $ git push origin ....


=item *

Create a tarball. Use the C<-s> option to specify a suitable suffix for
the tarball and directory name:

    $ cd root/of/perl/tree
    $ make distclean
    $ git clean -xdf		#  make sure perl and git agree on files

    $ perl Porting/makerel -b -s `git describe` # for a snapshot
    $ perl Porting/makerel -b -s RC1            # for a release candidate
    $ perl Porting/makerel -b                   # for a final release

This creates the  directory F<../perl-x.y.z-RC1> or similar, copies all
the MANIFEST files into it, sets the correct permissions on them,
adds DOS line endings to some, then tars it up as
F<../perl-x.y.z-RC1.tar.gz>. With C<-b>, it also creates a C<tar.bz2> file.

XXX if we go for extra tags and branches stuff, then add the extra details
here

=item *

Clean up the temporary directory, e.g.

    $ rm -rf ../perl-x.y.z-RC1

=item *

Copy the tarballs (.gz and possibly .bz2) to a web server somewhere you
have access to.

=item *

Download the tarball to some other machine. For a release candidate, 
you really want to test your tarball on two or more different platforms
and architectures. The #p5p IRC channel on irc.perl.org is a good place
to find willing victims.

=item *

Check that basic configuration and tests work on each test machine:

    $ ./Configure -des && make all test

=item *

Check that the test harness and install work on each test machine:

    $ make distclean
    $ ./Configure -des -Dprefix=/install/path && make all test_harness install
    $ cd /install/path

=item *

Check that the output of C<perl -v> and C<perl -V> are as expected,
especially as regards version numbers, patch and/or RC levels, and @INC
paths. 

Note that the results may be different without a F<.git/> directory,
which is why you should test from the tarball.

=item *

Compare the pathnames of all installed files with those of the previous
release (i.e. against the last installed tarball on this branch which you
have previously verified using this same procedure). In particular, look
for files in the wrong place, or files no longer included which should be.
For example, suppose the about-to-be-released version is 5.10.1 and the
previous is 5.10.0:

    cd installdir-5.10.0/
    find . -type f | perl -pe's/5\.10\.0/5.10.1/g' | sort > /tmp/f1
    cd installdir-5.10.1/
    find . -type f | sort > /tmp/f2
    diff -u /tmp/f[12]

=item *

Bootstrap the CPAN client on the clean install:

    $ ./bin/perl -MCPAN -e'shell' 

=item *

Try installing a popular CPAN module that's reasonably complex and that
has dependencies; for example:

    CPAN> install Inline
    CPAN> quit

Check that your perl can run this:

    $ ./bin/perl -lwe 'use Inline C => "int f() { return 42;} "; print f'
    42
    $

=item *

Bootstrap the CPANPLUS client on the clean install:

    $ ./bin/cpanp

=item *

Install an XS module, for example:

    CPAN Terminal> i DBI
    CPAN Terminal> quit
    $ bin/perl -MDBI -e 1


=item *

I<You MAY SKIP this step for SNAPSHOT>

Check that the C<perlbug> utility works. Try the following:

    $ bin/perlbug
    ...
    Subject: test bug report
    Local perl administrator [yourself]: 
    Editor [vi]: 
    Module: 
    Category [core]: 
    Severity [low]: 
    (edit report)
    Action (Send/Display/Edit/Subject/Save to File): f
    Name of file to save message in [perlbug.rep]: 
    Action (Send/Display/Edit/Subject/Save to File): q

and carefully examine the output (in F<perlbug.rep]>), especially
the "Locally applied patches" section. If everything appears okay, then
try it again, this time actually submitting the bug report. Check that it
shows up, then remember to close it!

=item *

I<You MAY SKIP this step for SNAPSHOT>

Wait for the smoke tests to catch up with the commit which this release is
based on (or at least the last commit of any consequence).

Then check that the smoke tests pass (particularly on Win32). If not, go
back and fix things.


=item *

I<You MUST SKIP this step for SNAPSHOT>

Once smoking is okay, upload it to PAUSE. This is the point of no return.
If anything goes wrong after this point, you will need to re-prepare
a new release with a new minor version or RC number.

    https://pause.perl.org/

(Login, then select 'Upload a file to CPAN')

Upload both the .gz and .bz2 versions of the tarball.

=item *

I<You MUST SKIP this step for SNAPSHOT>

Create a tag for the exact git revision you built the release from.
C<commit> below is the commit corresponding to the tarball. It can be
omitted if there have been no further commits since the tarball was
created.

    $ git tag perl-5.10.1-RC1 -m'Release Candidate 1 of Perl 5.10.1' <commit>
    $ git push origin tag perl-5.10.1-RC1

=item *

I<You MUST SKIP this step for SNAPSHOT>

Disarm the F<patchlevel.h> change; for example,

     static const char * const local_patches[] = {
             NULL
    -        ,"RC1"
             PERL_GIT_UNPUSHED_COMMITS /* do not remove this line */

Be sure to commit your change:

    $ git commit -m 'disarm RCnnn bump' patchlevel.h
    $ git push origin ....


=item *

Mail p5p to announce your new release, with a quote you prepared earlier.

=item *

I<You MAY SKIP this step for SNAPSHOT>

Wait 24 hours or so, then post the announcement to use.perl.org.
(if you don't have access rights to post news, ask someone like Rafael to
do it for you.)

=item *

I<You MUST SKIP this step for SNAPSHOT>

Ask Jarkko to add the tarball to http://www.cpan.org/src/

=item *

I<You MUST SKIP this step for SNAPSHOT, RC, BLEAD>

Ask Jarkko to update the descriptions of which tarballs are current in
http://www.cpan.org/src/README.html, and Rafael to update
http://dev.perl.org/perl5/

=item *

I<You MUST SKIP this step for SNAPSHOT, RC>

Create a new empty perlNNNdelta.pod file for the current release + 1;
see F<Porting/how_to_write_a_perldelta.pod>.
[ XXX Perhaps we should have an empty template file we can copy in. ]

In addition, edit F<pod.lst>, adding the new entry as 'D', and unmark previous
entry as 'D',

Change perlNNNdelta references to the new version in these files

    INSTALL
    win32/Makefile.mk
    win32/Makefile
    Makefile.SH
    README

Also, edit the previous delta file to change the C<NAME> from C<perldelta>
to C<perlNNNdelta>.

These two lists of files probably aren't exhaustive; do a recursive grep
on the previous filename to look for suitable candidates.

(see 16410843ea for an example).

=item *

Run C<perl pod/buildtoc --build-all> to update the following files:

    MANIFEST
    pod/perl.pod
    win32/pod.mak
    vms/descrip_mms.template

If you modified perldelta.pod, (F<vms/descrip_mms.template> will
needs a manual edit to bump the C<perldelta.pod> entry - it would
be good for someone to figure out the fix.)

=item *

I<You MUST SKIP this step for SNAPSHOT, RC, BLEAD>

If this was a maint release, then edit F<Porting/mergelog> to change
all the C<d> (deferred) flags to C<.> (needs review).

=item *

I<You MUST SKIP this step for SNAPSHOT, RC, BLEAD>

If this was a major release (5.x.0), then create a new maint branch 
based on the commit tagged as the current release and bump the version 
in the blead branch in git, e.g. 5.12.0 to 5.13.0.

[ XXX probably lots more stuff to do, including perldelta,
C<lib/feature.pm> ]

XXX need a git recipe

=item *

I<You MUST SKIP this step for SNAPSHOT, RC, BLEAD>

Copy the perlNNNdelta.pod for this release into the other branches, and
remember to update these files on those branches too:

    MANIFEST
    pod.lst
    pod/perl.pod
    vms/descrip_mms.template
    win32/pod.mak

(see fc5be80860 for an example).

=item *

I<You MUST SKIP this step for SNAPSHOT>

Make sure any recent F<pod/perlhist.pod> entries are copied to
F<perlhist.pod> on other branches; typically the RC* and final entries,
e.g.

          5.8.9-RC1     2008-Nov-10
          5.8.9-RC2     2008-Dec-06
          5.8.9         2008-Dec-14

=item *

I<You MUST SKIP this step for SNAPSHOT, RC>

Remind the current maintainer of C<Module::CoreList> to push a new release
to CPAN.

=item *

I<You MUST RETIRE to your preferred PUB, CAFE or SEASIDE VILLA for some much-needed
rest and relaxation>. 

Thanks for releasing perl!

=back

=head1 SOURCE

Based on
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2009-05/msg00608.html,
plus a whole bunch of other sources, including private correspondence.

=cut