perlpolicy
(1)
Name
perlpolicy - Various and sundry policies and commitments
related to the perl core
Synopsis
Please see following description for synopsis
Description
Perl Programmers Reference Guide PERLPOLICY(1)
NAME
perlpolicy - Various and sundry policies and commitments
related to the perl core
DESCRIPTION
This document is the master document which records all
written policies about how the Perl 5 Porters collectively
develop and maintain the Perl core.
MAINTENANCE AND SUPPORT
Perl 5 is developed by a community, not a corporate entity.
Every change contributed to the Perl core is the result of a
donation. Typically, these donations are contributions of
code or time by individual members of our community. On
occasion, these donations come in the form of corporate or
organizational sponsorship of a particular individual or
project.
As a volunteer organization, the commitments we make are
heavily dependent on the goodwill and hard work of
individuals who have no obligation to contribute to Perl.
That being said, we value Perl's stabilty and security and
have long had an unwritten covenant with the broader Perl
community to support and maintain releases of Perl.
This document codifies the support and maintenance
commitments that the Perl community should expect from
Perl's developers:
o We "officially" support the two most recent stable
release series'. As of the release of 5.14.0, we will
"officially" end support for Perl 5.10, other than
providing security updates as described below.
o To the best of our ability, we will attempt to fix
critical issues in the two most recent stable 5.x
release series'. Fixes for the current release series
take precedence over fixes for the previous release
series.
o To the best of our ability, we will provide "critical"
security patches / releases for any major version of
Perl initially released within the past three years. We
can only commit to providing these for the most recent
.y release in any 5.x.y series.
o We will not provide security updates or bug fixes for
development releases of Perl.
o We encourage vendors to ship the most recent supported
release of Perl at the time of their code freeze.
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o As a vendor, you may have a requirement to backport
security fixes beyond our 3 year support commitment. We
can provide limited support and advice to you as you do
so and, where possible will try to apply those patches
to the relevant -maint branches in git, though we may or
may not choose to make numbered releases or "official"
patches available. Contact us at
<perl5-security-report@perl.org> to begin that process.
BACKWARD COMPATIBILITY AND DEPRECATION
Our community has a long-held belief that backward-
compatibility is a virtue, even when the functionality in
question is a design flaw.
We would all love to unmake some mistakes we've made over
the past decades. Living with every design error we've ever
made can lead to painful stagnation. Unwinding our mistakes
is very, very difficult. Doing so without actively harming
our users is nearly impossible.
Lately, ignoring or actively opposing compatibility with
earlier versions of Perl has come into vogue. Sometimes, a
change is proposed which wants to usurp syntax which
previously had another meaning. Sometimes, a change wants
to improve previously-crazy semantics.
Down this road lies madness.
Requiring end-user programmers to change just a few language
constructs, even language constructs which no well-educated
developer would ever intentionally use is tantamount to
saying "you should not upgrade to a new release of Perl
unless you have 100% test coverage and can do a full manual
audit of your codebase." If we were to have tools capable
of reliably upgrading Perl source code from one version of
Perl to another, this concern could be significantly
mitigated.
We want to ensure that Perl continues to grow and flourish
in the coming years and decades, but not at the expense of
our user community.
Existing syntax and semantics should only be marked for
destruction in very limited circumstances. If a given
language feature's continued inclusion in the language will
cause significant harm to the language or prevent us from
making needed changes to the runtime, then it may be
considered for deprecation.
Any language change which breaks backward-compatibility
should be able to be enabled or disabled lexically. Unless
code at a given scope declares that it wants the new
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behavior, that new behavior should be disabled. Which
backward-incompatible changes are controlled implicitly by a
'use v5.x.y' is a decision which should be made by the
pumpking in consultation with the community.
When a backward-incompatible change can't be toggled
lexically, the decision to change the language must be
considered very, very carefully. If it's possible to move
the old syntax or semantics out of the core language and
into XS-land, that XS module should be enabled by default
unless the user declares that they want a newer revision of
Perl.
Historically, we've held ourselves to a far higher standard
than backward-compatibility -- bugward-compatibility. Any
accident of implementation or unintentional side-effect of
running some bit of code has been considered to be a feature
of the language to be defended with the same zeal as any
other feature or functionality. No matter how frustrating
these unintentional features may be to us as we continue to
improve Perl, these unintentional features often deserve our
protection. It is very important that existing software
written in Perl continue to work correctly. If end-user
developers have adopted a bug as a feature, we need to treat
it as such.
New syntax and semantics which don't break existing language
constructs and syntax have a much lower bar. They merely
need to prove themselves to be useful, elegant, well
designed and well tested.
Terminology
To make sure we're talking about the same thing when we
discuss the removal of features or functionality from the
Perl core, we have specific definitions for a few words and
phrases.
experimental
If something in the Perl core is marked as experimental,
we may change its behaviour, deprecate or remove it
without notice. While we'll always do our best to smooth
the transition path for users of experimental features,
you should contact the perl5-porters mailinglist if you
find an experimental feature useful and want to help
shape its future.
deprecated
If something in the Perl core is marked as deprecated,
we may remove it from thecore in the next stable release
series, though we may not. As of Perl 5.12, deprecated
features and modules warn the user as they're used. If
you use a deprecated feature and believe that its
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removal from the Perl core would be a mistake, please
contact the perl5-porters mailinglist and plead your
case. We don't deprecate things without a good reason,
but sometimes there's a counterargument we haven't
considered. Historically, we did not distinguish
between "deprecated" and "discouraged" features.
discouraged
From time to time, we may mark language constructs and
features which we consider to have been mistakes as
discouraged. Discouraged features aren't candidates for
removal in the next major release series, but we may
later deprecate them if they're found to stand in the
way of a significant improvement to the core.
removed
Once a feature, construct or module has been marked as
deprecated for a stable release cycle, we may remove it
from the core. Unsurprisingly, we say we've removed
these things.
MAINTENANCE BRANCHES
o New releases of maint should contain as few changes as
possible. If there is any question about whether a
given patch might merit inclusion in a maint release,
then it almost certainly should not be included.
o Portability fixes, such as changes to Configure and the
files in hints/ are acceptable. Ports of Perl to a new
platform, architecture or OS release that involve
changes to the implementation are NOT acceptable.
o Documentation updates are acceptable.
o Patches that add new warnings or errors or deprecate
features are not acceptable.
o Patches that fix crashing bugs that do not otherwise
change Perl's functionality or negatively impact
performance are acceptable.
o Patches that fix CVEs or security issues are acceptable,
but should be run through the
perl5-security-report@perl.org mailing list rather than
applied directly.
o Updates to dual-life modules should consist of minimal
patches to fix crashing or security issues (as above).
o New versions of dual-life modules should NOT be imported
into maint. Those belong in the next stable series.
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o Patches that add or remove features are not acceptable.
o Patches that break binary compatibility are not
acceptable. (Please talk to a pumpking.)
Getting changes into a maint branch
Historically, only the pumpking cherry-picked changes from
bleadperl into maintperl. This has...scaling problems. At
the same time, maintenance branches of stable versions of
Perl need to be treated with great care. To that end, we're
going to try out a new process for maint-5.12.
Any committer may cherry-pick any commit from blead to
maint-5.12 if they send mail to perl5-porters announcing
their intent to cherry-pick a specific commit along with a
rationale for doing so and at least two other committers
respond to the list giving their assent. (This policy
applies to current and former pumpkings, as well as other
committers.)
CONTRIBUTED MODULES
A Social Contract about Artistic Control
What follows is a statement about artistic control, defined
as the ability of authors of packages to guide the future of
their code and maintain control over their work. It is a
recognition that authors should have control over their
work, and that it is a responsibility of the rest of the
Perl community to ensure that they retain this control. It
is an attempt to document the standards to which we, as Perl
developers, intend to hold ourselves. It is an attempt to
write down rough guidelines about the respect we owe each
other as Perl developers.
This statement is not a legal contract. This statement is
not a legal document in any way, shape, or form. Perl is
distributed under the GNU Public License and under the
Artistic License; those are the precise legal terms. This
statement isn't about the law or licenses. It's about
community, mutual respect, trust, and good-faith
cooperation.
We recognize that the Perl core, defined as the software
distributed with the heart of Perl itself, is a joint
project on the part of all of us. From time to time, a
script, module, or set of modules (hereafter referred to
simply as a "module") will prove so widely useful and/or so
integral to the correct functioning of Perl itself that it
should be distributed with Perl core. This should never be
done without the author's explicit consent, and a clear
recognition on all parts that this means the module is being
distributed under the same terms as Perl itself. A module
author should realize that inclusion of a module into the
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Perl core will necessarily mean some loss of control over
it, since changes may occasionally have to be made on short
notice or for consistency with the rest of Perl.
Once a module has been included in the Perl core, however,
everyone involved in maintaining Perl should be aware that
the module is still the property of the original author
unless the original author explicitly gives up their
ownership of it. In particular:
o The version of the module in the core should still be
considered the work of the original author. All
patches, bug reports, and so forth should be fed back to
them. Their development directions should be respected
whenever possible.
o Patches may be applied by the pumpkin holder without the
explicit cooperation of the module author if and only if
they are very minor, time-critical in some fashion (such
as urgent security fixes), or if the module author
cannot be reached. Those patches must still be given
back to the author when possible, and if the author
decides on an alternate fix in their version, that fix
should be strongly preferred unless there is a serious
problem with it. Any changes not endorsed by the author
should be marked as such, and the contributor of the
change acknowledged.
o The version of the module distributed with Perl should,
whenever possible, be the latest version of the module
as distributed by the author (the latest non-beta
version in the case of public Perl releases), although
the pumpkin holder may hold off on upgrading the version
of the module distributed with Perl to the latest
version until the latest version has had sufficient
testing.
In other words, the author of a module should be considered
to have final say on modifications to their module whenever
possible (bearing in mind that it's expected that everyone
involved will work together and arrive at reasonable
compromises when there are disagreements).
As a last resort, however:
If the author's vision of the future of their module is
sufficiently different from the vision of the pumpkin holder
and perl5-porters as a whole so as to cause serious problems
for Perl, the pumpkin holder may choose to formally fork the
version of the module in the core from the one maintained by
the author. This should not be done lightly and should
always if at all possible be done only after direct input
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from Larry. If this is done, it must then be made explicit
in the module as distributed with Perl core that it is a
forked version and that while it is based on the original
author's work, it is no longer maintained by them. This
must be noted in both the documentation and in the comments
in the source of the module.
Again, this should be a last resort only. Ideally, this
should never happen, and every possible effort at
cooperation and compromise should be made before doing this.
If it does prove necessary to fork a module for the overall
health of Perl, proper credit must be given to the original
author in perpetuity and the decision should be constantly
re-evaluated to see if a remerging of the two branches is
possible down the road.
In all dealings with contributed modules, everyone
maintaining Perl should keep in mind that the code belongs
to the original author, that they may not be on
perl5-porters at any given time, and that a patch is not
official unless it has been integrated into the author's
copy of the module. To aid with this, and with points #1,
#2, and #3 above, contact information for the authors of all
contributed modules should be kept with the Perl
distribution.
Finally, the Perl community as a whole recognizes that
respect for ownership of code, respect for artistic control,
proper credit, and active effort to prevent unintentional
code skew or communication gaps is vital to the health of
the community and Perl itself. Members of a community
should not normally have to resort to rules and laws to deal
with each other, and this document, although it contains
rules so as to be clear, is about an attitude and general
approach. The first step in any dispute should be open
communication, respect for opposing views, and an attempt at
a compromise. In nearly every circumstance nothing more
will be necessary, and certainly no more drastic measure
should be used until every avenue of communication and
discussion has failed.
CREDITS
Social Contract about Contributed Modules originally by Russ
Allbery <rra@stanford.edu> and the perl5-porters.
ATTRIBUTES
See attributes(5) for descriptions of the following
attributes:
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+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------+
|Availability | runtime/perl-512 |
+---------------+------------------+
|Stability | Uncommitted |
+---------------+------------------+
NOTES
This software was built from source available at
https://java.net/projects/solaris-userland. The original
community source was downloaded from
http://www.cpan.org/src/5.0/perl-5.12.5.tar.bz2
Further information about this software can be found on the
open source community website at http://www.perl.org/.
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