Unstable `lockfree boost::atomic_flag` capability on MacOS Mojave over rebuild

[klirichek]

./bootstrap.sh --prefix=/work/boost/build --with-libraries=context
./b2
Performing configuration checks

    - default address-model    : 64-bit
    - default architecture     : x86

Building the Boost C++ Libraries.


    - symlinks supported       : yes
    - C++11 mutex              : no
    - lockfree boost::atomic_flag : no
...

then remove ./bin.v2 folder and try again with b2:

./b2
Performing configuration checks

    - default address-model    : 64-bit
    - default architecture     : x86

Building the Boost C++ Libraries.


    - symlinks supported       : yes
    - C++11 mutex              : no
    - lockfree boost::atomic_flag : yes

Note that lockfree boost::atomic_flag became 'yes' on second pass.

[stale[bot]]

Thank you for your contributions. Main development of B2 has moved to https://github.com/bfgroup/b2 This issue has been automatically marked as "transition" to indicate the potential for needing transition to the new B2 development project.