One possibility is the host ran out of space. From the “Linux_for_Tegra/bootloader/” location of the host PC, is there free space left? The command “df -H .” can help with that (the “.” means the current directory). The other possibility is a bug mentioned here:
https://forums.developer.nvidia.com/t/failed-to-sparse-the-raw-to-img-due-to-the-size-of-system-img-raw-is-not-mulple-of-4096/215526
I suggest combining your question in that thread.