message: Diagnose download problem?
diff: echo "Downloading Linux toolchain"
  -wget -q https://cdn.unrealengine.com/CrossToolchain_Linux/v19_clang-11.0.1-centos7.exe
  +wget https://cdn.unrealengine.com/CrossToolchain_Linux/v19_clang-11.0.1-centos7.exe
  +echo "Finished download"
  chmod a+x v19_clang-11.0.1-centos7.exe
  ./v19_clang-11.0.1-centos7.exe "//S"
  