F37 Change: Boost 1.78 upgrade (System-Wide Change proposal)

[Ben Cotton]

https://fedoraproject.org/wiki/Changes/F37Boost178

== Summary ==
This change brings Boost 1.78 to Fedora. This will mean Fedora ships
with a recent upstream Boost release.

== Owner ==

* Name: [[User:trodgers| Thomas Rodgers]]
* Email: [e-mail]

== 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/F35Boost176]], [[Changes/F34Boost175]],
[[Changes/F33Boost173]], [[Changes/F30Boost169|Fedora 30 Change]],
[[Changes/F29Boost167|Fedora 29 Change]], [[Changes/F28Boost166|Fedora
28 Change]], [[Changes/F27Boost164|Fedora 27 Change]],
[[Changes/F26Boost163|Fedora 26 Change]], [[Changes/F25Boost161|Fedora
25 Change]], [[Changes/F24Boost160|Fedora 24 Change]],
[[Changes/F23Boost159|Fedora 23 Change]] and
[[Changes/F22Boost158|Fedora 22 Change]].

== Benefit to Fedora ==

Fedora 37 includes Boost 1.78.

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

Boost 1.78 does not bring any new components, but includes two new
header-only libraries from Boost 1.77 -
* Describe: A C++14 reflection library. Provides macros for describing
enumerators and struct/class members, and primitives for querying this
information.
* Lambda2: A C++14, dependency-free, single header lambda library.
Allows simple function objects to be constructed via expressions such
as _1 + 5, _1 % 2 == 0, _1 > _2, or _1 == ' ' || _1 == '\t'.

Boost 1.78 also includes many fixes and enhancements to existing components.

== Scope ==
* Proposal owners:
** Build will be done with Boost.Build v2 (which is the
upstream-sanctioned way of building Boost)
** Request a "f37-boost"
[https://docs.pagure.org/releng/sop_adding_side_build_targets.html
build system tag]
([http://lists.fedoraproject.org/pipermail/devel/2011-November/159908.html
discussion]):

** Build boost into that tag (take a look at the
[http://koji.fedoraproject.org/koji/buildinfo?buildID=606493 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 <!-- [https://pagure.io/releng/issue/9421
#9421] --> (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:
<code>$ dnf repoquery -s --releasever=rawhide --whatrequires
libboost* --disablerepo=* --enablerepo=fedora | sort -u</code>

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

== Contingency Plan ==

* Contingency mechanism: Worst case scenario is to abandon the update
and simply ship F37 with Boost 1.76, which is already in rawhide.
* Blocks release? No
* Blocks product? None

== Documentation ==
* https://www.boost.org/users/history/version_1_78_0.html (released on
8th December 2021)
* https://www.boost.org/users/history/version_1_77_0.html (released on
11 August 2021)
* https://www.boost.org/development/index.html

== Release Notes ==

[Miro Hrončok]

On 23. 02. 22 17:48, Ben Cotton wrote:
> ** Request a "f37-boost"
> [https://docs.pagure.org/releng/sop_adding_side_build_targets.html
> build system tag]
> ([http://lists.fedoraproject.org/pipermail/devel/2011-November/159908.html
> discussion]):
>
> ** Build boost into that tag

Hey Thomas,

when do you expect to do this? Is there an estimated schedule? I recall some 
side tag conflicts between Python and Boost in the past, so we better 
coordinate. See our dates in:

https://fedoraproject.org/wiki/Changes/Python3.11#Important_dates_and_plan

Thanks,

[Thomas Rodgers]

I started on it in anger last week. I've been tracking down some breakage
in the upstream's build build that was preventing me from getting a
successful .rpm build, so I haven't even started to evaluate dependent
package breakage. I expect to have a scratch build done by this time
tomorrow.

On Tue, Mar 8, 2022 at 1:02 PM Miro Hrončok  wrote:
> On 23. 02. 22 17:48, Ben Cotton wrote:
> > ** Request a "f37-boost"
> > [https://docs.pagure.org/releng/sop_adding_side_build_targets.html
> > build system tag]
> > ([
>
> http://lists.fedoraproject.org/pipermail/devel/2011-November/159908.html
> > discussion]):
> >
> > ** Build boost into that tag
>
> Hey Thomas,
>
> when do you expect to do this? Is there an estimated schedule? I recall
> some
> side tag conflicts between Python and Boost in the past, so we better
> coordinate. See our dates in:
>
> https://fedoraproject.org/wiki/Changes/Python3.11#Important_dates_and_plan
> Thanks,
> Miro Hrončok
>
> Phone: [phone]
> IRC: mhroncok

[Thomas Rodgers]

I have completed mock builds of roughly 70% of the Boost dependent packages
in Fedora rawhide as of today. There have been no FTBFS issues related to
the upgrade to Boost 1.78.0.

Fesco approved the change proposal last week, I have confidence that this
version of Boost is stable enough to proceed with.

On Tue, Mar 8, 2022 at 6:12 PM Thomas Rodgers  wrote:
> I started on it in anger last week. I've been tracking down some breakage
> in the upstream's build build that was preventing me from getting a
> successful .rpm build, so I haven't even started to evaluate dependent
> package breakage. I expect to have a scratch build done by this time
> tomorrow.
>
> On Tue, Mar 8, 2022 at 1:02 PM Miro Hrončok  wrote:
> > On 23. 02. 22 17:48, Ben Cotton wrote:
> > > ** Request a "f37-boost"
> > > [https://docs.pagure.org/releng/sop_adding_side_build_targets.html
> > > build system tag]
> > > ([
> >
> > http://lists.fedoraproject.org/pipermail/devel/2011-November/159908.html
> > > discussion]):
> > >
> > > ** Build boost into that tag
> >
> > Hey Thomas,
> >
> > when do you expect to do this? Is there an estimated schedule? I recall
> > some
> > side tag conflicts between Python and Boost in the past, so we better
> > coordinate. See our dates in:
> >
> > https://fedoraproject.org/wiki/Changes/Python3.11#Important_dates_and_plan
> > Thanks,
> > Miro Hrončok
> >
> > Phone: [phone]
> > IRC: mhroncok