Yeah, I searched and searched and tried and tried, and now I'm posting ...
A couple weeks ago, I did a regular update of my 14.04.5 LTS system, and now it's giving me the error "package system is broken". It says to try two things:
Disable any third party PPAs. I checked my sources list (in the Ubuntu Software Center) and there weren't any. They're all ubuntu.com sources. OK, no, there is a Google source, but disabling it didn't help anything.
Run "sudo apt-get install -f", which gave me the output below. That output implies that my disk is full, but according to df it is definitely not. Seems like the problem is elsewhere but it's causing apt-get to think the drive is full.
command-prompt$ sudo apt-get install -f Reading package lists... Done Building dependency tree Reading state information... Done Correcting dependencies... Done The following packages were automatically installed and are no longer required: account-plugin-windows-live gir1.2-gnomekeyring-1.0 gir1.2-rb-3.0 gir1.2-secret-1 libdmapsharing-3.0-2 libgpod-common libgpod4 libhdb9-heimdal libkdc2-heimdal libllvm3.5 libntdb1 librhythmbox-core8 libsgutils2-2 libupstart1 linux-headers-3.13.0-117 linux-headers-3.13.0-117-generic linux-headers-3.16.0-30 linux-headers-3.16.0-30-generic linux-headers-4.4.0-34 linux-headers-4.4.0-34-generic linux-headers-4.4.0-45 linux-headers-4.4.0-45-generic linux-headers-4.4.0-64 linux-headers-4.4.0-64-generic linux-image-3.16.0-30-generic linux-image-4.4.0-34-generic linux-image-4.4.0-64-generic linux-image-extra-3.16.0-30-generic linux-image-extra-4.4.0-34-generic linux-image-extra-4.4.0-64-generic media-player-info python-ntdb python3-mako python3-markupsafe rhythmbox-data Use 'apt-get autoremove' to remove them. The following extra packages will be installed: linux-headers-3.13.0-129 linux-headers-3.13.0-129-generic linux-headers-4.4.0-91 The following NEW packages will be installed: linux-headers-3.13.0-129 linux-headers-3.13.0-129-generic linux-headers-4.4.0-91 0 upgraded, 3 newly installed, 0 to remove and 49 not upgraded. 4 not fully installed or removed. Need to get 0 B/19.5 MB of archives. After this operation, 149 MB of additional disk space will be used. Do you want to continue? [Y/n] y (Reading database ... 1695950 files and directories currently installed.) Preparing to unpack .../linux-headers-4.4.0-91_4.4.0-91.114~14.04.1_all.deb ... Unpacking linux-headers-4.4.0-91 (4.4.0-91.114~14.04.1) ... dpkg: error processing archive /var/cache/apt/archives/linux-headers-4.4.0-91_4.4.0-91.114~14.04.1_all.deb (--unpack): unable to create `/usr/src/linux-headers-4.4.0-91/drivers/staging/android/ion/Makefile.dpkg-new' (while processing `./usr/src/linux-headers-4.4.0-91/drivers/staging/android/ion/Makefile'): No space left on device No apport report written because the error message indicates a disk full error dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) Preparing to unpack .../linux-headers-3.13.0-129_3.13.0-129.178_all.deb ... Unpacking linux-headers-3.13.0-129 (3.13.0-129.178) ... dpkg: error processing archive /var/cache/apt/archives/linux-headers-3.13.0-129_3.13.0-129.178_all.deb (--unpack): unable to create `/usr/src/linux-headers-3.13.0-129/arch/mips/include/asm/lasat/head.h.dpkg-new' (while processing `./usr/src/linux-headers-3.13.0-129/arch/mips/include/asm/lasat/head.h'): No space left on device No apport report written because the error message indicates a disk full error dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) Preparing to unpack .../linux-headers-3.13.0-129-generic_3.13.0-129.178_amd64.deb ... Unpacking linux-headers-3.13.0-129-generic (3.13.0-129.178) ... dpkg: error processing archive /var/cache/apt/archives/linux-headers-3.13.0-129-generic_3.13.0-129.178_amd64.deb (--unpack): error creating directory `./usr/src/linux-headers-3.13.0-129-generic/include/config/module/sig': No space left on device No apport report written because the error message indicates a disk full error dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) Errors were encountered while processing: /var/cache/apt/archives/linux-headers-4.4.0-91_4.4.0-91.114~14.04.1_all.deb /var/cache/apt/archives/linux-headers-3.13.0-129_3.13.0-129.178_all.deb /var/cache/apt/archives/linux-headers-3.13.0-129-generic_3.13.0-129.178_amd64.deb E: Sub-process /usr/bin/dpkg returned an error code (1)