bad impl … logging in c10, but it relys on the FLAGS_caffe2_log_level ?  … 
but i found that it can print the LOG(INFO) in python frontend when building pytorch with USE_GLOG=1 (default GOOGLE_STRIP_LOG = 0)
for example
export CMAKE_PREFIX_PATH=${CONDA_PREFIX:-"$(dirname $(which conda))/../"}

MACOSX_DEPLOYMENT_TARGET=10.9 CC=clang CXX=clang++ MAX_JOBS=32 BUILD_CAFFE2=0 BUILD_CAFFE2_OPS=0 USE_GLOG=1 USE_DISTRIBUTED=1 USE_MKLDNN=0 USE_CUDA=0 USE_FBGEMM=0 USE_NNPACK=0 USE_QNNPACK=0 USE_XNNPACK=0 python setup.py develop