F39 proposal: Perl 5.38 (System-Wide Change proposal)

[Ben Cotton]

https://fedoraproject.org/wiki/Changes/perl5.38

This document represents a proposed Change. As part of the Changes
process, proposals are publicly announced in order to receive
community feedback. This proposal will only be implemented if approved
by the Fedora Engineering Steering Committee.

== Summary ==
A new ''perl 5.38'' version brings a lot of changes done over a year
of development. Perl 5.38 will be released in May 20th 2023. See
[https://metacpan.org/release/SHAY/perl-5.37.11/view/pod/perldelta.pod
perldelta for 5.37.11] for more details about new release.

== Owner ==
* Name: [[User:Jplesnik| Jitka Plesníková]], [[User:Mspacek| Michal
Josef Špaček]]
* Email: ,

== Current status ==

=== Completed Items ===

=== Items in Progress ===

=== Items to Be Done ===

* Get dedicated build-root from rel-engs (''f39-perl'')
* Upstream to release Perl 5.38
* Define perl_bootstrap in perl-srpm-macros
* Rebase perl to 5.38.0
* Rebuild all dual-lived packages (83) - otherwise dnf recommends
--skip-broken and fails
* Rebuild packages needed for minimal build-root
* Rebuild packages needed for building source packages from git repository
* Rebuild packages requiring ''libperl.so'' or versioned
''perl(MODULE_COMPAT)'': Use Fedora::Rebuild dependency solver
* Undefine perl_bootstrap
* Rebuild packages having perl_bootstrap condition in spec file (XX packages)
* Rebuild all updated packages
* [https://jplesnik.fedorapeople.org/5.38/ Final lists of results]
* Merge dedicated build-root to rawhide and remove the dedicated one by rel-engs
* Synchronize packages upgraded in ''f39'' build root
* Rebuild Perl packages: 0 of 600 done (0 %)
* Failed packages (0):
* Rebuild Fedora modules: 0 of 0 (0 %)
* Create module perl:5.38 and rebuild dependencies

== Detailed Description ==
New perl is released every year and updates containing mainly bug
fixes follow during the year. The 5.38.0 version is stable release
this year.

== Benefit to Fedora ==

Up-to-date and latest perl release will be delivered to Fedora users.

== Scope ==
Every Perl package will be rebuilt in a dedicated ''f39-perl''
build-root against perl 5.38.0 and then if no major problem emerges
the packages will be merged back to ''f39'' build-root.

* Proposal owners: New perl and all packages requiring ''libperl.so''
or versioned ''perl(MODULE_COMPAT)'' will be rebuilt into ''f39-perl''
build-root.

* Other developers: Owners of packages that fail to rebuild, mainly
perl-sig users, will be asked using Bugzilla to fix or remove their
packages from the distribution.

* Release engineering: [https://pagure.io/releng/issues #Releng issue
number] <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
Release engineers will be asked for new ''f39-perl'' build-root
inheriting from ''f39'' build-root. After successful finishing the
rebuild, they will be asked to merge ''f39-perl'' packages back to
''f39'' build-root.

* Policies and guidelines: N/A (not needed for this Change)

* Trademark approval: N/A (not needed for this Change)

* Alignment with Objectives:

== Upgrade/compatibility impact ==
Vast majority of functionality will be preserved. Only the packages
that failed to build against perl 5.38 will be removed from the
distribution. That will require to remove those packages from the
existing systems otherwise a package manager will encounter
unsatisfied dependencies. The developers in Perl language are advised
to install ''perl-doc'' and ''perl-debugger'' packages.

== How To Test ==
Try upgrading from Fedora 38 to 39. Try some Perl application to
verify they work as expected. Try embedded perl in
[https://src.fedoraproject.org/rpms/openldap slapd] or
[https://src.fedoraproject.org/rpms/net-snmp snmpd].

== User Experience ==
There should not be any remarkable change in user experience. With the
exception that previously locally installed modules with a CPAN
clients will need a reinstallation.

== Dependencies ==
There is more than 3500 packages depending on perl. It is the first
rebuild where we will rebuild only all dual-lived packages and
packages which require ''libperl.so'' or versioned
''perl(MODULE_COMPAT)''. It means only about 600 packages needs to
rebuild. Most of them are expected not to break. Finishing this change
can be endangered only by critical changes in a toolchain.
''noarch'' packages don't need to be rebuilt now.

== Contingency Plan ==
* Contingency mechanism: If we find perl 5.38 is not suitable for
Fedora 39, we will revert back to perl 5.36 and we drop the temporary
build-root with already rebuilt packages.
* Contingency deadline: branching Fedora 39 from Rawhide.
* Blocks release? No.

== Documentation ==
* 5.38.0 perldelta
* An announcement on perl-devel mailing list
* An announcement on fedora-devel mailing list

== Release Notes ==
TBD