crash on install BASE_SNAPSHOT

[fawqsir]

Changed a few lines because I was not able to create a subvolume with: btrfs subv create /mnt/@snapshots/system/$BASE_SNAPSHOT

Line 89: btrfs subv create /mnt/@aal/snapshots
to
btrfs subv create /mnt/@snapshots

line 96: mkdir /mnt/@aal/snapshots/system /mnt/@aal/snapshots/etc /mnt/@aal/snapshots/work-etc
to
mkdir /mnt/@snapshots/system /mnt/@snapshots/etc /mnt/@snapshots/work-etc

....

Still crashes on line below. Not sure why... when I ssh into the virtual machine. I tried changing from /bin/ash to /bin/sh, but makes no difference. When I cut and past the line it works. However within the script it stops on this line.
BASE_SNAPSHOT="$(date -u +"%Y-%m-%d_%H:%M:%S")_$(cat /dev/urandom | tr -dc 'a-zA-Z' | fold -w 8 | head -n 1)"