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Perl 5.20


A new perl 5.20 version brings a lot of changes done over a year of development. See 5.20.0 perldelta for more details.


Current status

Completed items

  • Get dedicated build-root from rel-engs (f22-perl)
  • Rebase perl to 5.20.0
  • Define perl_bootstrap in perl-srpm-macros
  • Build new perl 5.20 keeping old COMPAT Provides
  • Rebuild packages needed for minimal build-root
  • Rebuild dual-lived packages (otherwise yum recommends --skip-broken and fails)
  • Rebuild packages needed for building source packages from git repository
  • Remove old perl(:MODULE_COMPAT_5.18.*) from perl
  • Undefine perl_bootstrap
  • Rebuild packages having perl_bootstrap condition in spec file
  • Merge dedicated build-root to rawhide and remove the dedicated one by rel-engs.
  • Synchronize packages upgraded in f22 build root

Items in progress

  • Rebuilt Perl packages: 2563 of 2564 done (99.96 %)
  • Rebuild other packages: Use Fedora::Rebuild dependency solver

Items to be done

  • Failed rebuilds (1 including intermittent failures):
    • Sprog - fails in rawhide [1]

Detailed Description

New perl is released every year and updates containing mainly bug fixes follow during the year. The 5.20.0 version is stable release this year.

Benefit to Fedora

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


Every Perl package will be rebuilt in a dedicated f22-perl build-root against perl 5.20.0 and then if no major problem emerges the packages will be merged back to f22 build-root.

  • Proposal owners:

New perl and all packages requiring perl or a Perl module will be rebuilt into f22-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:

Release engineers will be asked for new f22-perl build-root inheriting from f22 build-root. After successful finishing the rebuild, they will be asked to merge f22-perl packages back to f22 build-root.

  • Policies and guidelines:

No policies have to be modified to complete this change.

Upgrade/compatibility impact

Vast majority of functionality will be preserved. Only the packages that failed to build against perl 5.20 will be removed from the distribution. That will require to remove those packages from existing systems otherwise package manager will encounter unsatisfied dependencies.

How To Test

Try upgrading from Fedora 21 to 22. Try some Perl application to verify they work as expected. Try embedded perl in slapd or snmpd.

User Experience

There should not be any remarkable change in user experience.


There is more than 2000 packages depending on perl. Most of them are expected not to break. Finishing this change can be endangered only by critical changes in a toolchain.

Contingency Plan

If we find perl 5.20 is not suitable for Fedora 22, we will revert back to perl 5.18 and we drop the temporary build-root with already rebuilt packages.

  • Contingency deadline: branching Fedora 22 from Rawhide.
  • Blocks release? No.


Release Notes

  • New features:
    • Subroutine prototype attribute allows to declare subroutine prototype in postfix manner.
    • Hash-slice %hash{...} syntax returns subset as a hash.
    • Unicode 6.3 tables added.
    • More internal counters support 64-bit values (arrays with more than 2^32 elements, regular expression matching strings longer than 2^32 characters).
    • Copy-on-write mechanism is used when assigning scalars.
    • Speed was improved (lazy evaluation of logical conjunction and disjunction in void context, constant hash look-ups, return at the end of subroutine).
    • New modules were added into the core (experimental, IO::Socket::IP).
  • Changes:
    • use locale in an UTF-8 locale environment enables Unicode character type processing.
    • perl initializes locale according to all locale environment variables (like LANG).
    • -F perl option implies -a option.
    • -a perl option implies -n option.
    • Character after \c sequence in double-quoted string or regular expression must be a printable character and may not be a {.
    • In use locale scope, regular expression matching which depends on locale properties (like case) taints values.
    • \p{} and \P{} Unicode property tests handle non-Unicode code points as unassigned characters. On the other hand, \P{All} matches any code points (in contrast to \P{Any}.
    • Data::Dumper output format has changed.
    • Locale decimal point in Perl code is subject to locale only in scope of use locale.
  • Removed features:
    • do subroutine(LIST) is not supported anymore and results into a syntax error.
    • PerlIO_vsprintf() and PerlIO_sprintf() functions have been removed.