I am unable to build the current version of the runtime with debug symbols. I just added -DCMAKE_BUILD_TYPE=Debug to the CMake call.
HPX: 35428360f0cbde7f9ff697008649dbc75c0a67e2
API: c81015dc5339a9af834c5d760fe3ca18636bbf5c
The full log file can be found here.