Still broken: boost.

In file included from ./boost/interprocess/detail/os_file_functions.hpp:40:0,
                 from ./boost/interprocess/mapped_region.hpp:29,
                 from libs/log/src/posix/ipc_reliable_message_queue.cpp:51:
./boost/interprocess/detail/os_file_functions.hpp:636:16: error: stray ‘@’ in program
    while((de=::readdir(d))) {
[...]
build of /gnu/store/j29v8ph3asv4sywi0437hs6wwd9knvy2-boost-1.74.0.drv failed

That means that boost, or that source file, is not being compiled with
_FILE_OFFSET_BITS=64 .

Nowhere does the header file boost/interprocess/detail/os_file_functions.hpp
even check the value of _FILE_OFFSET_BITS.

./libs/filesystem/src/platform_config.hpp is responsible for setting up
_FILE_OFFSET_BITS in general.

That means that platform_config.hpp is not being #included in the former.

boost/interprocess/errors.hpp:// Parts of this code are taken from boost::filesystem library
boost/interprocess/errors.hpp://  See library home page at http://www.boost.org/libs/filesystem

But that means that this does not USE the "filesystem" library and neither does
it set _FILE_OFFSET_BITS like the "filesystem" library would.

All this happens even after I added a phase to gnu-build-system to set
_FILE_OFFSET_BITS unconditionally, so boost ignores that, too.