ISO image maker compiling failures

[alexmacrae]

Scratching my head over the image compile script failing. ref: https://github.com/alexmacrae/SamplerBox/blob/master/isoimage/samplerbox_iso_maker.sh

It seems calling both systemctl stop serial-getty@ttyAMA0.service and/or systemctl enable /etc/systemd/system/samplerbox.service at the end of the script is causing this fail message:

Failed to get D-Bus connection: Unknown error -1 ref: https://github.com/alexmacrae/SamplerBox/blob/master/isoimage/samplerbox_iso_maker.sh#L308

Prior to this I it was failing at the very end trying to umount devices:

umount: /home/pi/SamplerBox/img_maker/sdcard: target is busy
        (In some cases useful info about processes that
         use the device is found by lsof(8) or fuser(1).)
device-mapper: remove ioctl on loop0p3 failed: Device or resource busy
device-mapper: remove ioctl on loop0p2 failed: Device or resource busy
device-mapper: remove ioctl on loop0p1 failed: Device or resource busy

ref: https://github.com/alexmacrae/SamplerBox/blob/master/isoimage/samplerbox_iso_maker.sh#L321

There's also the reoccurring fail message Failed to read /proc/cmdline. Ignoring: No such file or directory - however I'm sure I've noticed this appear previously on what would become a successful compile.

Are all, or some of these things related?

[alexmacrae]

Other errors that have occurred in the past around the same point in the script:

samplerbox_img_maker.sh: 1: samplerbox_img_maker.sh: y: not found
Failed to read /proc/cmdline. Ignoring: No such file or directory
Created symlink from /etc/systemd/system/local-fs.target.wants/samplerbox.service to /etc/systemd/system/samplerbox.service.
umount: /home/pi/SamplerBox/img_maker/sdcard/boot (/dev/mapper/loop0p1) unmounted
umount: /home/pi/SamplerBox/img_maker/sdcard/samples (/dev/mapper/loop0p3) unmounted
umount: /home/pi/SamplerBox/img_maker/sdcard (/dev/mapper/loop0p2) unmounted
del devmap : loop0p3
device-mapper: remove ioctl on loop0p2 failed: Device or resource busy
del devmap : loop0p1
loop deleted : /dev/loop0

and

samplerbox_img_maker.sh: 1: samplerbox_img_maker.sh: y: not found
Failed to read /proc/cmdline. Ignoring: No such file or directory
Failed to get D-Bus connection: Unknown error -1

and

umount: /home/pi/SamplerBox/img_maker/sdcard: target is busy
        (In some cases useful info about processes that
         use the device is found by lsof(8) or fuser(1).)
device-mapper: remove ioctl on loop0p3 failed: Device or resource busy
device-mapper: remove ioctl on loop0p2 failed: Device or resource busy
device-mapper: remove ioctl on loop0p1 failed: Device or resource busy
loop deleted : /dev/loop0
umount: /home/pi/SamplerBox/img_maker/sdcard/boot (/dev/mapper/loop0p1) unmounted
umount: /home/pi/SamplerBox/img_maker/sdcard/samples (/dev/mapper/loop0p3) unmounted