sudo mkdir -p ~/rpi_mnt
pi@raspberrypi48:~ $ sudo losetup -f -P --show /mnt/runimg/readynas_compile_tool.img
/dev/loop0
pi@raspberrypi48:~ $ sudo mount /dev/loop0p2 -o rw ~/rpi_mnt
pi@raspberrypi48:~ $ cd ~/rpi_mnt
pi@raspberrypi48:~/rpi_mnt $ sudo mount --bind /dev ~/rpi_mnt/dev/
pi@raspberrypi48:~/rpi_mnt $ sudo mount --bind /sys ~/rpi_mnt/sys/
pi@raspberrypi48:~/rpi_mnt $ sudo mount --bind /proc ~/rpi_mnt/proc/
pi@raspberrypi48:~/rpi_mnt $ sudo mount --bind /dev/pts ~/rpi_mnt/dev/pts
pi@raspberrypi48:~/rpi_mnt $ sudo mkdir -p  /media/netdir/source/raspberrypi/4-07
pi@raspberrypi48:~/rpi_mnt $ sudo mkdir -p  ~/rpi_mnt/mnt/compile
pi@raspberrypi48:~/rpi_mnt $ sudo mount  --bind  /media/netdir/source/raspberrypi/4-07 ~/rpi_mnt/mnt/compile
pi@raspberrypi48:~/rpi_mnt $ cd ~/rpi_mnt
pi@raspberrypi48:~/rpi_mnt $ sudo chroot . bin/bash
root@raspberrypi48:/# 
root@raspberrypi48:/# ls -l
total 64
drwxr-xr-x   2 root root 4096 Jan  1 14:39 bin
drwxr-xr-x   2 root root 4096 Jun 17  2018 boot
drwxr-xr-x  18 root root 4040 Jan  7 14:01 dev
drwxr-xr-x  66 root root 4096 Jan  1 11:11 etc
drwxr-xr-x   2 root root 4096 Jun 17  2018 home
drwxr-xr-x  12 root root 4096 Jan  1 10:34 lib
drwx------   2 root root 4096 Jan  1 14:39 lost+found
drwxr-xr-x   2 root root 4096 Jan  1 14:39 media
drwxr-xr-x   3 root root 4096 Jan  1 14:39 mnt
drwxr-xr-x   2 root root 4096 Jan  1 14:39 opt
dr-xr-xr-x 180 root root    0 Jan  1  1970 proc
drwx------   2 root root 4096 Jan  1 10:09 root
drwxr-xr-x   4 root root 4096 Jan  1 10:03 run
drwxr-xr-x   2 root root 4096 Jan  1 10:03 sbin
drwxr-xr-x   2 root root 4096 Jan  1 14:39 srv
dr-xr-xr-x  12 root root    0 Jan  7 13:10 sys
drwxrwxrwt   2 root root 4096 Jan  1 14:14 tmp
drwxr-xr-x  10 root root 4096 Jan  1 14:39 usr
drwxr-xr-x  11 root root 4096 Jan  1 14:39 var
root@raspberrypi48:/# echo 00:00:00
00:00:00
root@raspberrypi48:/# date
Tue Jan  7 14:01:15 UTC 2020
root@raspberrypi48:/# 
root@raspberrypi48:/# 
root@raspberrypi48:/# compile finish
bash: compile: command not found
root@raspberrypi48:/# exit
exit
pi@raspberrypi48:~/rpi_mnt $ cd 
pi@raspberrypi48:~ $ sudo umount  ~/rpi_mnt/mnt/compile
pi@raspberrypi48:~ $ sudo umount  ~/rpi_mnt/dev/pts
pi@raspberrypi48:~ $ sudo umount  ~/rpi_mnt/proc
pi@raspberrypi48:~ $ sudo umount  ~/rpi_mnt/sys
pi@raspberrypi48:~ $ sudo umount  ~/rpi_mnt/dev
pi@raspberrypi48:~ $ sudo umount  ~/rpi_mnt
pi@raspberrypi48:~ $ sudo losetup -d  /dev/loop0
pi@raspberrypi48:~ $