tegra-ubuntu? You seem to be using Jetson-TK1 or other non-x86_64 architecture. While you can build some targets for ARM, this is way less explored path than x86_64 Linux.
Change UEBuildLinux.cs to return default architecture as arm-unknown-linux-gnueabihf (look for DefaultArchitecture name in line 26) and try again.
Note that building the editor on Jetson is theoretically possible, but you will need code changes to remove certain libraries which don’t have ARM version (e.g. FBX SDK). I stronly suggest that you build on x86_64 machine first and then use that experience, build on ARM.