autoinstall disk full error not understandable

I ran into an issue when the disk partition is not large enough for the install, with a very generic error.

'returned non-zero exit status 3' (see attachment).

Upon digging into the issue, I found that it was failing when attempting to run the following command:

unshare --fork --pid -- chroot /target eatmydata apt-get --quiet --assume-yes --option=Dpkg:options::=--force-unsafe-io --option=Dpkg:Options::=--force-confold install linux-generic

The '--quiet' flag hid the fact that there was no disk space left. When running the command manually, without the flag, it exposed the issue.

Please add extra output to this line, so that other people don't have to spend hours tracking down the issue.

Thanks in advance,
-Brian Metzler