Changes/F39Boost181

Boost 1.81 upgrade

Summary

This change brings Boost 1.81 to Fedora. This will mean Fedora ships with a recent upstream Boost release.

Owner

• Name: Thomas Rodgers
• Email: trodgers@redhat.com

Current status

• Targeted release: Fedora 39
• Last updated: 2023-01-04
• devel thread
• FESCo issue: #2918
• Tracker bug: #2158241
• Release notes tracker: #946

Detailed Description

The aim is to synchronize Fedora with the most recent Boost release. Because ABI stability is absent from Boost, this entails rebuilding of all dependent packages. This also entails the change owner assisting maintainers of client packages in decoding cryptic boost-ese seen in output from g++.

The equivalent changes for previous releases were Changes/F37Boost178, Changes/F35Boost176, Changes/F34Boost175, Changes/F33Boost173, Fedora 30 Change, Fedora 29 Change, Fedora 28 Change, Fedora 27 Change, Fedora 26 Change, Fedora 25 Change, Fedora 24 Change, Fedora 23 Change and Fedora 22 Change.

Benefit to Fedora

Fedora 39 includes Boost 1.81.

Fedora will stay relevant, as far as Boost clients are concerned.

Boost 1.81 does not bring any new components, but includes one new header-only library -

• URL: Boost.URL is a portable C++ library which provides containers and algorithms which model a URL.

Boost 1.81 also includes many fixes and enhancements to existing components, including major and potentially breaking changes to -

• Container Hash: removal of specializations to boost::hash, removal of support for BOOST_HASH_NO_EXTENSION, improved performance and quality of generated hashes.
• Locale: Removal of C++03 support, C++11 or later is now required (BREAKING CHANGE)

Boost 1.81 includes additional enhancements and breaking changes from Boost 1.80 and Boost 1.79 -

• Filesystem: boost/filesystem/string_file.hpp header is deprecated and no longer included by boost/filesystem.hpp
• GIL: Deprecates C++11 support, C++14 will be the new minimum language standard.
• Math: Deprecates C++11 support, C++14 will be the new minimum language standard.
• Multiprecision: Deprecates C++11 support, C++14 will be the new minimum language standard.

Scope

• Proposal owners:
  • Build will be done with Boost.Build v2 (which is the upstream-sanctioned way of building Boost)
  • Request a "f39-boost" build system tag (discussion):

• • Build boost into that tag (take a look at the build #606493 for inspiration)
  • Post a request for rebuilds to fedora-devel
  • Work on rebuilding dependent packages in the tag.
  • When most is done, re-tag all the packages to rawhide
  • Watch fedora-devel and assist in rebuilding broken Boost clients (by fixing the client, or Boost).

• Other developers:
  • Those who depend on Boost DSOs will have to rebuild their packages. Feature owners will alleviate some of this work as indicated above, and will assist those whose packages fail to build in debugging them.

• Release engineering: TODO (a check of an impact with Release Engineering is needed)

• Policies and guidelines:
  • Apart from scope, this is business as usual, so no new policies, no new guidelines.

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

Upgrade/compatibility impact

• No manual configuration or data migration needed.
• Some impact on other packages needing code changes to rebuild. Historically this hasn't been too much of a problem and could always be resolved before deadline.

How To Test

• No special hardware is needed.
• Integration testing simply consists of installing Boost packages (dnf install boost) on Fedora and checking that it does not break other packages (see below for a way to obtain a list of boost clients).

User Experience

• Expected to remain largely the same.
• Developers building third-party software on Fedora may need to rebuild against the new Boost packages, and may need to adjust their code if the new Boost release is not source-compatible.

Dependencies

Packages that must be rebuilt: $ dnf repoquery -s --releasever=rawhide --whatrequires libboost\* --disablerepo=* --enablerepo=fedora | sort -u

All clients: $ dnf repoquery --releasever=rawhide --archlist=src --whatrequires boost-devel --disablerepo='*' --enablerepo=fedora-source

Contingency Plan

• Contingency mechanism: Worst case scenario is to abandon the update and simply ship F39 with Boost 1.78, which is already in rawhide.

• Blocks release? No
• Blocks product? None

Documentation

• https://www.boost.org/users/history/version_1_81_0.html (expected release mid December 2022)
• https://www.boost.org/users/history/version_1_79_0.html (released on 10th August 2022)
• https://www.boost.org/users/history/version_1_79_0.html (released on 13th April 2022)
• https://www.boost.org/development/index.html