I’m running LinuxMint 19.3 and with default setup, sdkmanager won’t work and flashing will fail.
Download sdkmanager form NVidia’s website and install it
Make a back of you lsb-release file
sudo cp /etc/lsb-release /etc/lsb-release_backup
Modify the /etc/lsb-release file to make sdkmanager know it’s an Ubuntu based system
DISTRIB_ID=Ubuntu DISTRIB_RELEASE=18.04.4 DISTRIB_CODENAME=tricia DISTRIB_DESCRIPTION="Linux Mint 19.3 Tricia"
Now install these packages
apt install binfmt-support apt install qemu-user-static
If qemu-user-static was previously installed, re-configure it
Now you can run sdkmanager and flash your tegra devices.