Bug#588715: grub-probe fails to find a device for /

[Adam C. Emerson]

Package: grub-common
Version: 1.98-1
Severity: normal

First noticed within the past week while trying to upgrade memtest86+,
the grub-probe program complains:
grub-probe: error: cannot find a device for / (is /dev mounted?).

It gives the same error when invoked directly from the command line.
/dev is, in fact, mounted.  The output of mount shows:
/dev/mapper/c--68--40--176--142-root on / type ext4 (rw,user_xattr,errors=remount-ro)
Verifying that with file gives:
/dev/mapper/c--68--40--176--142-root: symbolic link to `../dm-0'
And verifying that gives:
/dev/dm-0: block special


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

Kernel: Linux 2.6.32-5-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages grub-common depends on:
ii  base-files              5.7              Debian base system miscellaneous f
ii  dpkg                    1.15.7.2         Debian package management system
ii  gettext-base            0.18-1           GNU Internationalization utilities
ii  install-info            4.13a.dfsg.1-5   Manage installed documentation in 
ii  libc6                   2.11.2-2         Embedded GNU C Library: Shared lib
ii  libfreetype6            2.3.11-1         FreeType 2 font engine, shared lib
ii  zlib1g                  1:1.2.3.4.dfsg-3 compression library - runtime

Versions of packages grub-common recommends:
ii  os-prober                     1.38       utility to detect other OSes on a 

Versions of packages grub-common suggests:
pn  grub-emu                      <none>     (no description available)
pn  multiboot-doc                 <none>     (no description available)

-- no debconf information