Bug#741726: grub: generated grub.cfg leads to non booting system. Drops to rescue shell after not finding root device.

[root]

Source: grub
Version: 2.02~beta2-7
Severity: critical
Justification: breaks the whole system

Dear Maintainer,

grub: generated grub.cfg leads to non booting system. Drops to rescue shell after not finding root device.

Updating from older grub to grub 2.02~ beta2-7
update-grub - generated same config file again -> boots into rescue-mode


-- System Information:
Debian Release: jessie/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.10.32-std420-amd64 (SMP w/1 CPU core)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash