ninja: Entering directory `out/gn'
[1/3] ACTION //libcxx/include:write_modulemap(//llvm/utils/gn/build/toolchain:unix)
[2/3] COPY ../../libcxx/include/__flat_set/flat_set.h include/c++/v1/__flat_set/flat_set.h
[3/3] COPY ../../libcxx/include/__flat_set/utils.h include/c++/v1/__flat_set/utils.h