ninja: Entering directory `out/gn'
[1/4] COPY ../../libcxx/include/__type_traits/common_reference.h include/c++/v1/__type_traits/common_reference.h
[2/4] COPY ../../libcxx/include/__functional/reference_wrapper.h include/c++/v1/__functional/reference_wrapper.h
[3/4] COPY ../../libcxx/include/functional include/c++/v1/functional
[4/4] COPY ../../libcxx/include/version include/c++/v1/version