update-grub reports grep error 'input file ... is also the output'

[Rocko]

I upgraded from oneiric to precise after backing up my oneiric partition to /dev/sda5, and when I run update-grub I get this error:

Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.3.0-rc5-git-20120226.0832
Found initrd image: /boot/initrd.img-3.3.0-rc5-git-20120226.0832
Found linux image: /boot/vmlinuz-3.2.9-generic
Found initrd image: /boot/initrd.img-3.2.9-generic
Found linux image: /boot/vmlinuz-3.2.0-17-generic
Found initrd image: /boot/initrd.img-3.2.0-17-generic
Found linux image: /boot/vmlinuz-3.0.0-16-generic
Found initrd image: /boot/initrd.img-3.0.0-16-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Ubuntu 11.10 (11.10) on /dev/sda5
grep: input file U+2018/boot/grub/grub.cfg.newU+2019 is also the output

The resulting grub.cfg file has this entry:

### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Debian, with Linux 3.3.0-rc5-git-20120226.0832 (on /dev/sda5)" --class gnu-linux --class gnu --class os {
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos5)'
 search --no-floppy --fs-uuid --set=root 193832bf-63d7-4129-99f5-3ca3e1daa470
 linux /boot/vmlinuz-3.3.0-rc5-git-20120226.0832 root=UUID=67083065-b92e-4596-a218-817c1dfc8ae7 ro i915.i915_enable_rc6=1 quiet splash vt.handoff=7
 initrd /boot/initrd.img-3.3.0-rc5-git-20120226.0832
}

ie grub has detected the oneiric backup partition, but failed to update the grub.cfg file correctly (the uuid for the 'search' is the correct uuid for this partition, but the uuid for the 'linux' entry is wrong).

Trying to boot from the oneiric partition of course then fails because it looks for the wrong partition.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: grub-pc 1.99-14ubuntu2
Uname: Linux 3.3.0-rc5-git-20120226.0832 x86_64
ApportVersion: 1.93-0ubuntu2
Architecture: amd64
Date: Fri Mar 2 22:41:45 2012
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
ProcEnviron:
 LANGUAGE=en_AU:en
 TERM=xterm
 LANG=en_AU.UTF-8
 SHELL=/bin/bash
SourcePackage: grub2
UpgradeStatus: Upgraded to precise on 2012-03-02 (0 days ago)