"Unmet Dependencies" problem when trying apt-get install

Question

Anytime I try to install python packages using the command:

sudo apt-get install python-package

I get the following output:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
 linux-headers-generic : Depends: linux-headers-3.2.0-36-generic but it is not going to be installed
 linux-headers-generic-pae : Depends: linux-headers-3.2.0-36-generic-pae but it is not going to be installed
 linux-image-generic : Depends: linux-image-3.2.0-36-generic but it is not going to be installed
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

This seems to have started when these same three packages showed up in Ubuntu's Update Manager and kicked an error when I tried to install them there. Based on the suggestion in the output above, I tried running:

sudo apt-get -f install

But this only gave me several instances of the following error:

dpkg: error processing /var/cache/apt/archives/linux-image-3.2.0-36-generic_3.2.0-36.57_i386.deb (--unpack):
 unable to create `/lib/modules/3.2.0-36-generic/kernel/drivers/net/wireless/ath/carl9170/carl9170.ko.dpkg-new' (while processing `./lib/modules/3.2.0-36-generic/kernel/drivers/net/wireless/ath/carl9170/carl9170.ko'): No space left on device

Now maybe I'm way off-base here, but I'm wondering if the error could be coming from the "No space left on device" part? The thing is, I'm running Ubuntu as a VirtualBox VM but I've got it set to dynamically increase its virtual hard drive space as needed, so why am I still getting this error?

Here's my output when I use dh -f:

Filesystem        Size  Used Avail Use% Mounted on
/dev/sda1         6.9G  5.7G  869M  88% /
udev              494M  4.0K  494M   1% /dev
tmpfs             201M  784K  200M   1% /run
none              5.0M     0  5.0M   0% /run/lock
none              501M   76K  501M   1% /run/shm
VB_Shared_Folder  466G  271G  195G  59% /media/sf_VB_Shared_Folder

When I perform sudo apt-get -f install and the system says,

After this operation, 192 MB of additional disk space will be used.

Does that mean 192 MB of my virtual machine's current memory, or 192 MB on top of the rest of my free space? As I said, my machine normally dynamically allocates additional memory from the host machine, so I don't see why there would be memory restrictions at all...

Solution 1

If, by any chance, you're using

sudo apt-get -f install python-package

try running

sudo apt-get -f install

(without any package name), and once this step is done with, try running the original command:

sudo apt-get install python-package

Solution 2

It's possible that the "No space left on device" error is related to the "unmet dependencies" problem. Either way, you have to fix both.

Check free space with any of these methods (such as df -h). If if you're low, free some up using these methods (removing old kernels; also applies when /boot is not a separate partition) and these methods (removing unused packages and cached package archives).

Especially if the "unmet dependencies" problem arose from software not being properly installed and configured after disk space ran out, you should be able to fix it simply:

sudo dpkg --configure -a
sudo apt-get update && sudo apt-get -f install

But if that doesn't work, don't fret--there are many other powerful (and easily applied) techniques for fixing "unmet dependencies":

• How do I resolve unmet dependencies after adding a PPA?

Comments

[GChorn]

Thank you for the answer. I've tried everything in your solution and on the page you linked me to, and I keep getting either E: Unmet dependencies. Try using -f. or E: Sub-process /usr/bin/dpkg returned an error code (1) or E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

[Eliah Kagan]

@GChorn So...what did you get from df -h?

[GChorn]

In /dev/sda1, I have 869MB of space left. That should be enough right?

[Eliah Kagan]

@GChorn That should be enough that low space on /dev/sda1 is not the cause of this problem, yes. There's other partitions though... can you edit your question to include the full output?

[GChorn]

Thanks for the answer. I tried this and got dpkg: error processing linux-headers-3.2.0-36_3.2.0-36.57_all.deb (--install): unable to create /usr/src/linux-headers-3.2.0-36/include/media/mt9p031.h.dpkg‌​-new' (while processing ./usr/src/linux-headers-3.2.0-36/include/media/mt9p031.h'): No space left on device which is basically the same error as when I tried apt-get -f install...