Hi - I am trying to flash GrapheneOS on a pixel 4XL and I am unsure whether the flash-all.sh script is running or whether I am ok to close the terminal. 

I followed the instructions on https://grapheneos.org/install/cli but after running ./flash-all.sh nothing has happened for 10 minutes. There is no output in the terminal and the phone screen remains unchanged (Fastboot Mode, device state: Unlocked)

I am going to try the next step in the troubleshooting (mkdir tmp && TMPDIR="$PWD/tmp" ./flash-all.sh) but I don't want to kill the terminal if it is actually flashing.

Thank you.