setup-disk does not write /tmp/alpine-install-diskmode.out when installing to a mount point
I set up my disks manually and run setup-alpine with an answer file that
DISKOPTS=“-m sys ‘/mnt’”
setup-disk does not write the mode to /tmp/alpine-install-diskmode.out
in this case. However, setup-alpine expects that file to always be
written and tries parsing it.
This leads to setup-alpine incorrectly running setup-lbu and setup-apkcache.
(from redmine: issue id 10444, created on 2019-05-11)