Comment 6 for bug 1406735

Thanks for the further debug output. In your first response I don't really understand the invoke-rc.d complaint about the symlink.

> dpkg-maintscript-helper: error: couldn't identify the package

Ah, I forgot about that. Try running it like that:

# env DPKG_MAINTSCRIPT_PACKAGE=udev DPKG_MAINTSCRIPT_NAME=postinst sh -ex /var/lib/dpkg/info/udev.postinst configure ; echo $?

So I don't understand why invoke-rc.d works fine when you call it directly, but complains about the rcS.d/ link (which looks fine) when being called through the postinst. So maybe above command will shed some light on this. If it still doesn't, you can also try to modify /var/lib/dpkg/info/udev.postinst to add an additional "set -x" as the second line, and run

  sudo dpkg-reconfigure udev