Why can't 'grub-mkconfig_lib` be opened, preventing a kernel upgrade?

Question

I try to update my Ubuntu 12.04 and I have this error, then it update kernel. Any clue what I can do to fix this?

sudo apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 2 not upgraded.
4 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Setting up linux-image-3.2.0-25-generic (3.2.0-25.40) ...
Running depmod.
update-initramfs: deferring update (hook will be called later)
Examining /etc/kernel/postinst.d.
run-parts: executing /etc/kernel/postinst.d/dkms 3.2.0-25-generic /boot/vmlinuz-3.2.0-25-generic
run-parts: executing /etc/kernel/postinst.d/initramfs-tools 3.2.0-25-generic /boot/vmlinuz-3.2.0-25-generic
update-initramfs: Generating /boot/initrd.img-3.2.0-25-generic
Warning: No support for locale: en_US.utf8
run-parts: executing /etc/kernel/postinst.d/pm-utils 3.2.0-25-generic /boot/vmlinuz-3.2.0-25-generic
run-parts: executing /etc/kernel/postinst.d/update-notifier 3.2.0-25-generic /boot/vmlinuz-3.2.0-25-generic
run-parts: executing /etc/kernel/postinst.d/zz-update-grub 3.2.0-25-generic /boot/vmlinuz-3.2.0-25-generic
Generating grub.cfg ...
/etc/grub.d/10_linux: 24: .: Can't open /usr/share/grub/grub-mkconfig_lib
run-parts: /etc/kernel/postinst.d/zz-update-grub exited with return code 2
Failed to process /etc/kernel/postinst.d at /var/lib/dpkg/info/linux-image-3.2.0-25-generic.postinst line 1010.
dpkg: error processing linux-image-3.2.0-25-generic (--configure):
 subprocess installed post-installation script returned error exit status 2
dpkg: dependency problems prevent configuration of linux-image-generic:
 linux-image-generic depends on linux-image-3.2.0-25-generic; however:
  Package linux-image-3.2.0-25-generic is not configured yet.
dpkg: error processing linux-image-generic (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of linux-generic:
 linux-generic depends on linux-image-generic (= 3.2.0.25.27); however:
  Package linux-image-generic is not configured yet.
dpkg: error processing linux-generic (--configure):
 dependency problems - leaving unconfigured
Setting up plymouth-theme-kubuntu-logo (1:12.04ubuntu4) ...
No apport report written because the error message indicates its a followup error from a previous failure.
                                                                                                          No apport report written because the error message indicates its a followup error from a previous failure.
                                                                                               update-initramfs: deferring update (trigger activated)
Generating grub.cfg ...
/etc/grub.d/10_linux: 24: .: Can't open /usr/share/grub/grub-mkconfig_lib
dpkg: error processing plymouth-theme-kubuntu-logo (--configure):
 subprocess installed post-installation script returned error exit status 2
No apport report written because MaxReports is reached already
                                                              Processing triggers for initramfs-tools ...
update-initramfs: Generating /boot/initrd.img-3.2.0-25-generic
Warning: No support for locale: en_US.utf8
Errors were encountered while processing:
 linux-image-3.2.0-25-generic
 linux-image-generic
 linux-generic
 plymouth-theme-kubuntu-logo
E: Sub-process /usr/bin/dpkg returned an error code (1)

Answer 1

I've pasted the content of /usr/share/grub/grub-mkconfig_lib here. You can download it and place it in appropriate place, then retry.

Also, look for the file /usr/lib/grub/grub-mkconfig_lib. Generally, it's a symbolic link to /usr/share/grub/grub-mkconfig_lib. But do check if the original file is there. If in your case /usr/lib/grub/grub-mkconfig_lib is the original file then open the file /etc/grub.d/10_linux and change its 22nd line from datarootdir="${prefix}/share" to datarootdir="${prefix}/lib" then complete the upgrade.