> cmake -H. -B_builds -DCMAKE_VERBOSE_MAKEFILE=ON
-- Boost version: 1.54.0
-- Found the following Boost libraries:
--   system
x: /usr/include
y: /usr/lib/x86_64-linux-gnu/libboost_system.so
> cmake --build _builds/
clang++ ... -rdynamic -lboost_system