canonical_device() + uswsusp + update_initramfs

Ubuntu 14.04.2 LTS
cryptsetup 2:1.6.1-1ubuntu1

Hello:

/usr/share/initramfs-tools/hooks/cryptroot calls
    resumedevs=$(get_resume_devices).
get_resume_devices() reads /etc/uswsusp.conf and finds in my case /dev/sda2. Then it calls canonical_device() for /dev/sda2.
canonical_device() throws
   "cryptsetup: WARNING: failed to detect canonical device of $original"
Thus /dev/sda2 never makes it into resumedevs.
I wonder if this is the root cause for my system does not boot anymore after installing uswsusp and running update-initramfs. The old initram image successfully boots. Thus the source for malfunction must be the initram image, not the kernel or something else.

By the way get_resume_devices() looks at several spots for a resume device. If the identical resume device is listed twice or more in different files in the same way then the doubles are discarded. If the identical resume device is listed twice or more in different files in different ways, e.g. one by lable and one by UUID, they are not identified as identical and an error message is thrown. Is this intended?

Best regards, Th.