can't create a backup (raspbian) -> freeze after truncate

[theoneandonly-vector]

----    Raspberry Pi clone to image V1.6    ---
-----------------------------------------------
---- DO NOT CHANGE FILES ON YOUR SD CARD    ---
---- WHILE THE BACKUP PROGRAM IS RUNNING    ---
---- THE DESTINATION .IMG FILE MUST BE      ---
---- ON AN EXTERNAL STORAGE / NETWORK SHARE ---
-----------------------------------------------
Cloning /dev/mmcblk0 to backup.img
Show progress is on.
uuid | cut -f1 -d-
sh: 1: uuid: not found
mktemp -d
mktemp -d
-----------------------------------------------
----    READING PARTITIONS               ------
-----------------------------------------------
Partition 1 start: 8192 end: 532479 ptype:primary ftype:fat32 flags: lba
.Partition 2 start: 532480 end: 62333951 ptype:primary ftype:ext4 flags:
.partprobe
Last partition starts at 272629760 bytes.
mount /dev/mmcblk0p2 /tmp/tmp.X7kYdEM6sl
df /tmp/tmp.X7kYdEM6sl | tail -n 1 | tr -s " " " " | cut -d ' ' -f 2
df /tmp/tmp.X7kYdEM6sl | tail -n 1 | tr -s " " " " | cut -d ' ' -f 4
Used size of last partition is 3086970880 bytes.
umount /tmp/tmp.X7kYdEM6sl
Required size for destination image: 3437278720 bytes
-----------------------------------------------
----    ALLOCATING SPACE FOR .IMG FILE   ------
-----------------------------------------------
touch "backup.img"
df "backup.img" | tail -n 1 | tr -s " " " " | cut -d ' ' -f 1
/dev/sdc1
df --output=avail -B 1 "backup.img" | tail -n 1
15427166208
truncate --size 3437278720 "backup.img"```

when I cancel using ctrl+c I cna see the file.

[tom-2015]

Can you check if the truncate command is still running in the background when the program hangs?