./gencpp-0.3.4-403d067.tar.gz already exists, skipping download
Getting https://github.com/ros/gencpp/archive/403d0672999d167c52fb48804034e9c3d69018d4/gencpp-0.3.4-403d067.tar.gz to ./gencpp-0.3.4-403d067.tar.gz