boost: update to 1.69.0

[michaelld (Michael Dickens)]

Boost 1.69.0 is out as of 12/12/2018.

Because the Portfile currently uses "--layout=tagged", the resulting libraries names change from the Boost 1.68.0 to include an abbreviated architecture (e.g., "x64" for Intel 64-bit; "p32" for PPC 32-bit); thus for example, the prior naming might be "libboost_system-mt.dylib", while the new naming is "libbboost_system-mt-x64.dylib". This slight change combined with a defect in how CMake works with Clang results in the FindBoost.cmake script failing to detect the new library names with significant coercion.

This issue is resolved by moving to "--layout=system", which reverts the library names to just the minimum for each component; for example here "libboost_system.dylib".

Most of the changes to this latest Boost itself seem to be compatible with the ports I've tried building with it, once the Portfile is fixed to properly detect the changed name. That said, the 10 or so ports I checked pale compared with the total number of ports that depend on Boost (some 250 in total).

Verifying that "enough" of these ports build and function properly "enough" is an arduous task. We in MacPorts have yet to determine a reasonable approach to updating Boost, so the version provided in MacPorts regularly lags the latest release. Please be patient.

[michaelld (Michael Dickens)]

OK so there are some issues I'm coming upon with changes to boost::thread and boost::posix_time ... hopefully it's just slopping programming on the project's part. Or maybe the Boost folks fixed some type conversation issues. I'll work on fixing & verify back backward compatibility with (at least) boost 1.66.0.

[elfprince13 (Thomas Dickerson)]

There are also some changes in the interaction between CMake and Boost::python, which may be non-backwards compatible.

[michaelld (Michael Dickens)]

Given the ~4 months for projects to fix their issues with Boost 1.67.0, and possible more issues now with 1.68.0, let's test this release with ports that require Boost to make sure the vast majority work. I would like to get this updated Boost in place sooner rather than later, assuming compatibility is good.

[michaelld (Michael Dickens)]

Updated the patch to reset the revision to 0.

[ryandesign (Ryan Carsten Schmidt)]

I'm not working on this; go ahead with what you think is best.

[michaelld (Michael Dickens)]

Updated the patch to remove part of a patchfile incorporated into Boost master for +python3X only.

[michaelld (Michael Dickens)]

One major ABI naming change: the Boost::Python library is renamed to include the major.minor Python version but with no "." ... so, "27" for Python 2.7 and "36" for Python 3.6 (for 2.,7 was "libboost_python-mt.dylib" is now "libboost_python27-mt.dylib"). Not sure if this is a change from 1.67.0 or 1.66.0 ... but it's important since any project using CMake to find Boost must now specify "python27" or "python36" as a component to look for, not just "python" or "python2" or "python3"; guessing other build systems will be impacted as well.

[michaelld (Michael Dickens)]

The ABI name change was in Boost 1.67.0 ... so, projects might already be updating to check for it. Not sure where CMake is on this change.

[michaelld (Michael Dickens)]

CMake is aware of this change: ​https://gitlab.kitware.com/cmake/cmake/blob/master/Modules/FindBoost.cmake#L43 . One just has to use the correct module name, which now depends on which version of Boost is installed ... so, some logic needs to be in place for projects looking for any Boost Python-based ABI (e.g., "python" or "numpy"). Fun fun!

[luzpaz]

FYI 1.69.0 is latest stable