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Boost 1.72 upgrade


This change brings Boost 1.72 to Fedora. This will mean Fedora ships with a recent upstream Boost release.


Current status

  • Targeted release: cancelled (was Fedora 32 )
  • Last updated: 2020-03-24
  • Tracker bug: #TBC (see also BZ#1558278)
  • Release notes tracker: #TBC

Detailed Description

The aim is to synchronize Fedora with the most recent Boost release. Because ABI stability is one of explicit Boost non-goals, this entails rebuilding of all dependent packages. This has also always entailed yours truly assisting maintainers of client packages in decoding cryptic boost-ese seen in output from g++. Such care is to be expected this time around as well.

The equivalent changes for previous releases were:

Benefit to Fedora

Fedora 31 includes Boost 1.69, but the latest upstream release, Boost 1.72, will be released in December 2019.

Fedora will stay relevant, as far as Boost clients are concerned. Boost 1.72 brings a few new components:

  • Boost.Variant2, a never-valueless, strong guarantee implementation of std::variant, from Peter Dimov.
  • Boost.Outcome, a set of tools for reporting and handling function failures in contexts where directly using C++ exception handling is unsuitable, from Niall Douglas.
  • Boost.Histogram, fast and extensible multi-dimensional histograms with convenient interface for C++14, from Hans Dembinski.


  • Proposal owners:
    • Build will be done with Boost.Build v2 (which is the upstream-curated way of building Boost)
    • Request a "f32-boost" build system tag (discussion), as for Boost 1.69 on Fedora 30:
    • 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: create an issue similar to f32-boost side tag (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 impact on system upgrade (no removed subpackages this time).
  • No manual configuration or data migration needed.
  • Some impact on other packages needing code changes to rebuild. Historically this hasn't been too big 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.


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 F32 with Boost 1.69, which is already in rawhide.
  • Contingency deadline: We will know whether the change can be made once the rebuilds in the side tag are done, which will be around December 2019, ideally before the mass rebuild.
  • Blocks release? No
  • Blocks product? None


Release Notes

Boost has been upgraded to version 1.72. Apart from a number of bug fixes and improvements to existing libraries, compared to Fedora 31, this brings: