I had also tried the 'touch /sbin/udevadm.upgrade' workaround, and it failed to work. However, instead of deleting the '--convert-db' line in /var/lib/dpkg/info/udev.postinst, I changed it from:
udevadm info --convert-db
to:
udevadm.upgrade info --convert-db
This let the install finish correctly, and the next time I edited the udev.postinst file, dpkg had changed it back to the original. Now back to fixing dependencies and then finishing my upgrade.
I had also tried the 'touch /sbin/udevadm. upgrade' workaround, and it failed to work. However, instead of deleting the '--convert-db' line in /var/lib/ dpkg/info/ udev.postinst, I changed it from:
udevadm info --convert-db
to:
udevadm.upgrade info --convert-db
This let the install finish correctly, and the next time I edited the udev.postinst file, dpkg had changed it back to the original. Now back to fixing dependencies and then finishing my upgrade.