Unable to Build linux_nvidia_jetson-l4t-32.5.1-2.1.0 on Jetson Nano B01 (4GB)

[estgv18632]

After download and running the setup (with "./setup Documents nano") successfully I get the following message on running the step 3:

itec@itec-desktop:~/Downloads/linux_nvidia_jetson-l4t-32.5.1-2.1.0/avt_build$ sudo ./build.sh Documents nano all all

[i]...Running script for building Linux4Tegra setup...
[d]...dedicated for L4T: R32.5.1 and Jetson ...
[i]...Export variables for compiling...
[d]...ARCH=arm64...
[d]...CROSS_COMPILE=/home/itec/Downloads/linux_nvidia_jetson-l4t-32.5.1-2.1.0/avt_build/Documents/gcc/gcc-7.3.1-aarch64/bin/aarch64-linux-gnu-...
[d]...INSTALL_MOD_PATH=/home/itec/Downloads/linux_nvidia_jetson-l4t-32.5.1-2.1.0/avt_build/Documents/Linux_for_Tegra/rootfs...
[i]...Clean kernel sources...
sudo: time: command not found
[d]...Could not clean kernel sources...
Failed...
[i]...Script execution...
Failed...

Any help is apprecciated.