BOOST 1.87 (And 1.88.0 beta1) Context: Removed support for building with ucontext?

[flarren1]

Hi,

I am currently using boost 1.84 in an application were I use boost context + boost fibers to achieve userland threading. This project also uses gcc sanitizers to check for vulnerabilities. Therefore I follow the instructions provided:
"Sanitizers (GCC/Clang) are confused by the stack switches. The library (and Boost.Context too) is required to be compiled with property (b2 command-line) context-impl=ucontext and compilers santizer options. Users must define BOOST_USE_ASAN before including any Boost.Context headers when linking against Boost binaries" (https://live.boost.org/doc/libs/1_87_0/libs/fiber/doc/html/fiber/stack/sanitizers.html)

This works fine for 1.84, but after trying to uplift to boost 1.87 i get the following issue:

./b2 -j8 define=BOOST_USE_UCONTEXT context-impl=ucontext
xxx/boost_1_87_0/tools/build/src/build/feature.jam:327: in validate-feature from module feature
error: unknown feature context-impl
xxx/boost_1_87_0/tools/build/src/build/feature.jam:361: in expand-subfeatures-aux from module feature
xxx/boost_1_87_0/tools/build/src/build/feature.jam:422: in feature.expand-subfeatures from module feature
xxx/ in apply-to-property-set from module build-request
(builtin):-1: in sequence.transform from module sequence
xxx/boost_1_87_0/tools/build/src/build/build-request.jam:32: in build-request.expand-no-defaults from module build-request
xxx/boost_1_87_0/tools/build/src/build-system.jam:778: in module scope from module build-system

The same command worked fine with 1.84 and I cannot see any differences in the documentation that says the feature flag has changed.
Any ideas?

Thanks and best regards
Anders

[flarren1]

I tried boost 1.88.0.beta1 and unfortunately the issue seems to remain there.
@olk Do you happen to know anything about removal of support for building with ucontext?

[flarren1]

The issue seems to be that the context impl-feature was not migrated from libs/context/build/Jamfile.v2 to
libs/context/boost-context-features.jam. This file does not exist in 1.84.

Other features like valgrind and segmented-stacks were already defined in boost-context-features.jam. Not sure if this was intentional or not. After adding context-impl to the features, it builds.

[flarren1]

What I describe above is already corrected by @grisumbras here 12ac945

However, it is not corrected in the offical release 1.87, nor in 1.88 beta1. Does anyone know the way of working here? I am new to the community, sorry :)

[flarren1]

I saw the mailing notification regarding freeze for 1.88: "Reminder: Master branch closes for the 1.88.0 release NEXT WEDNESDAY (2th April)"

The problem is already corrected on the develop branch in boost/context as far as I can see, however it is not included if you download the 1.88 beta1 package

I am happy to help out if needed, but as mentioned earlier I do not know exactly what is needed to be done. Is it a matter of updating the context submodule in the top repo?