$TMPDIR is not synced to the SDCard.

[kenfallon]

Apologies if I'm missing something obvious but I don't think that the $TMPDIR is synced to the SDCard.

write.sh has A tmp dir to store things in, a boot partition and the root filesystem TMPDIR=$(mktemp -d /tmp/writesdcard.XXXXXXXX) ROOT=$TMPDIR/root

Eventually the file dynamic-rootfs.sh has rootfs() which writes the files to the $TMPDIR/root.

I don't see anywhere where the files are then copied from the $TMPDIR to the real root on the SDCARD.