Comment 2 for bug 18391

I had the same problem. I used up pretty much of my space and saw that in /var/cache I had like 600MB so I did rm -rf /var/cache/* right after that apt-get and Synaptic returned errors when you would try to use them.

I searched in Google and of course many other folks have had the same issue which is fixed with mkdir -p /var/cache/apt/archives/partial. I do think this is an issue that have happened to many people and will happen in the future and it costs nothing to be fixed and not to couse an error when you have deleted all your /var/chache.

Kind regards!