In the latest Raspbian for Robots “Buster” beta release, it is not possible for apt to update the dhcpcd5 package. Attempting to upgrade this package returns the error:
dpkg: error processing package dhcpcd5 (--configure) installed dhcpcd5 package post-installation script subprocess returned error exit status 1
Further examination of the /var/log/apt/term.log disclosed an additional error message:
chown: changing ownership of '/etc/dhcpcd.conf' :| Operation not permitted.
I examined the directory entry for /etc/dhcpcd.conf and discovered that /etc/dhcpcd.conf is a symlink to /boot/network/dhcpcd.conf.
THIS is the problem:
“/boot” is located within a FAT filesystem. FAT filesystems do not support file ownership attributes, so the attempt to change them automatically fails.
I copied /boot/network/dhcpcd.conf to /etc, removing the symlink, and the update process was able to complete normally.
Since I don’t know if dhcpcd.conf is a necessary file in /boot/network, I copied the updated file back to /boot/network. That is, I am “assuming” it was updated since apt’s update process tried to do something to it.
I have NOT checked this against Stretch, nor have I compared this to a original download of Raspbian Buster from the Raspberry Pi Foundation.